File:Tohoku Population 1920-2020.svg

Created with Matplotlib in Python using the following code.

#!/usr/bin/env python

from matplotlib import pyplot
from matplotlib import ticker
from matplotlib import numpy

# This generates a line graph showing the population of prefectures
# in Tohoku, Japan.
# 
# Data spans 1920-2020, from October of each year.
# Recent data is from each prefecture's public announcements.
# Data for years ending in 0 and 5 are from the national census.
# The 1945 census was postponed and conducted in 1947.
#
# 1920-1995 data is in five year intervals, except for 1947.
# 2000-2020 data is annual.
#
# https://uub.jp/pjn/pb.html
#
# This file was written by Douglas Perkins.
# It is released under a Creative Commons Zero 1.0 dedication.
#
# https://creativecommons.org/publicdomain/zero/1.0/

aomori_data = [
(1920, 756454),  (1925, 812977),  (1930, 879914),  (1935, 967129),
(1940, 1000509), (1947, 1180245), (1950, 1282867), (1955, 1382523),
(1960, 1426606), (1965, 1416591), (1970, 1427520), (1975, 1468646),
(1980, 1523907), (1985, 1524448), (1990, 1482873), (1995, 1481663),
(2000, 1475728), (2001, 1472633), (2002, 1467788), (2003, 1459855), (2004, 1450622),
(2005, 1436657), (2006, 1423425), (2007, 1408663), (2008, 1394881), (2009, 1382637),
(2010, 1373339), (2011, 1363003), (2012, 1349899), (2013, 1336155), (2014, 1321863),
(2015, 1308265), (2016, 1293619), (2017, 1278450), (2018, 1262686), (2019, 1246138),
(2020, 1238730),
]

iwate_data = [
(1920, 845540),  (1925, 900984),  (1930, 975771),  (1935, 1046111),
(1940, 1095793), (1947, 1262743), (1950, 1346728), (1955, 1427097),
(1960, 1448517), (1965, 1411118), (1970, 1371383), (1975, 1385563),
(1980, 1421927), (1985, 1433611), (1990, 1416928), (1995, 1419505),
(2000, 1416180), (2001, 1413099), (2002, 1408079), (2003, 1401763), (2004, 1394810),
(2005, 1385041), (2006, 1374699), (2007, 1363702), (2008, 1352388), (2009, 1340852),
(2010, 1330147), (2011, 1312756), (2012, 1303351), (2013, 1294453), (2014, 1284384),
(2015, 1279594), (2016, 1268083), (2017, 1254807), (2018, 1240522), (2019, 1226430),
(2020, 1211206),
]

miyagi_data = [
(1920, 961768),  (1925, 1004036), (1930, 1142784), (1935, 1234801),
(1940, 1271238), (1947, 1566831), (1950, 1663442), (1955, 1727065),
(1960, 1743195), (1965, 1753126), (1970, 1819223), (1975, 1955267),
(1980, 2082320), (1985, 2176295), (1990, 2248558), (1995, 2328739),
(2000, 2365320), (2001, 2368591), (2002, 2370280), (2003, 2371683), (2004, 2370985),
(2005, 2360218), (2006, 2354992), (2007, 2348999), (2008, 2343767), (2009, 2340029),
(2010, 2348165), (2011, 2323224), (2012, 2325407), (2013, 2328143), (2014, 2327993),
(2015, 2333899), (2016, 2329431), (2017, 2322024), (2018, 2313215), (2019, 2303160),
(2020, 2303487),
]

akita_data = [
(1920, 898537),  (1925, 936408),  (1930, 987706),  (1935, 1037744),
(1940, 1052275), (1947, 1257398), (1950, 1309031), (1955, 1348871),
(1960, 1335580), (1965, 1279835), (1970, 1241376), (1975, 1232481),
(1980, 1256745), (1985, 1254032), (1990, 1227478), (1995, 1213667),
(2000, 1189279), (2001, 1183362), (2002, 1175855), (2003, 1167282), (2004, 1159139),
(2005, 1145501), (2006, 1134033), (2007, 1121347), (2008, 1109085), (2009, 1097626),
(2010, 1085997), (2011, 1075055), (2012, 1063168), (2013, 1050244), (2014, 1037060),
(2015, 1023119), (2016, 1009705), (2017, 995380),  (2018, 980694),  (2019, 965968),
(2020, 960113),
]

yamagata_data = [
(1920, 968925),  (1925, 1027297), (1930, 1080034), (1935, 1116822),
(1940, 1119338), (1947, 1335653), (1950, 1357347), (1955, 1353649),
(1960, 1320664), (1965, 1263103), (1970, 1225618), (1975, 1220302),
(1980, 1251917), (1985, 1261662), (1990, 1258390), (1995, 1256958),
(2000, 1244147), (2001, 1240877), (2002, 1235870), (2003, 1229854), (2004, 1223739),
(2005, 1216181), (2006, 1207513), (2007, 1198710), (2008, 1189152), (2009, 1179964),
(2010, 1168924), (2011, 1161294), (2012, 1151863), (2013, 1141260), (2014, 1130659),
(2015, 1123891), (2016, 1113029), (2017, 1101452), (2018, 1089806), (2019, 1077057),
(2020, 1068696),
]

fukushima_data = [
(1920, 1362750), (1925, 1437596), (1930, 1508150), (1935, 1581563),
(1940, 1625521), (1947, 1992460), (1950, 2062394), (1955, 2095237),
(1960, 2051137), (1965, 1983754), (1970, 1946077), (1975, 1970616),
(1980, 2035272), (1985, 2080304), (1990, 2104058), (1995, 2133592),
(2000, 2126935), (2001, 2124404), (2002, 2119382), (2003, 2112489), (2004, 2104850),
(2005, 2091319), (2006, 2080186), (2007, 2068352), (2008, 2055496), (2009, 2042816),
(2010, 2029064), (2011, 1988995), (2012, 1962333), (2013, 1947580), (2014, 1936630),
(2015, 1914039), (2016, 1900106), (2017, 1882666), (2018, 1865143), (2019, 1847950),
(2020, 1834198),
]

years = [d[0] for d in aomori_data]

aomori_populations = [d[1] for d in aomori_data]
iwate_populations = [d[1] for d in iwate_data]
miyagi_populations = [d[1] for d in miyagi_data]
akita_populations = [d[1] for d in akita_data]
yamagata_populations = [d[1] for d in yamagata_data]
fukushima_populations = [d[1] for d in fukushima_data]

# A formatter to display comma-separated numbers on the y axis.
def comma_func(y, pos):
	s = '{:0,d}'.format(int(y))
	return s

comma_format = ticker.FuncFormatter(comma_func)

# Make a bar graph.
x = numpy.arange(len(years)) + 0.25
width = 0.5
pyplot.figure(num=1, figsize=(7,4))
axis = pyplot.subplot(1, 1, 1)
axis.plot(years, aomori_populations, color='b')
axis.plot(years, iwate_populations, color='r')
axis.plot(years, miyagi_populations, color='g')
axis.plot(years, akita_populations, color='y')
axis.plot(years, yamagata_populations, color='m')
axis.plot(years, fukushima_populations, color='c')
axis.legend(["Aomori", "Iwate", "Miyagi", "Akita", "Yamagata", "Fukushima"])
axis.yaxis.set_major_formatter(comma_format)
axis.yaxis.set_major_formatter(comma_format)
axis.grid(b=True, axis='both')
axis.set_ylim([0, 2500000])
axis.set_xlim([1920, 2020])
pyplot.title('Tohoku Population 1920-2020')
pyplot.ylabel('People')
pyplot.xlabel('Year')
pyplot.xticks(numpy.arange(1920, 2021, 10))
pyplot.savefig('Tohoku Population 1920-2020.svg', format='svg', bbox_inches='tight')

I, the copyright holder of this work, hereby publish it under the following license:

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The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission. http://creativecommons.org/publicdomain/zero/1.0/deed.enCC0Creative Commons Zero, Public Domain Dedicationfalsefalse