Year	Measure
1820	822.6
1821	830
1822	837.5
1823	845.1
1824	852.8
1825	860.5
1826	868.3
1827	876.2
1828	884.1
1829	892.1
1830	900.2
1831	908.3
1832	916.5
1833	924.8
1834	933.2
1835	941.7
1836	950.2
1837	958.8
1838	967.5
1839	976.2
1840	985.1
1841	994
1842	1003
1843	1012
1844	1021
1845	1030
1846	1040
1847	1049
1848	1059
1849	1068
1850	1078
1851	1088
1852	1098
1853	1108
1854	1118
1855	1128
1856	1138
1857	1148
1858	1159
1859	1169
1860	1180
1861	1190
1862	1201
1863	1212
1864	1223
1865	1234
1866	1245
1867	1257
1868	1268
1869	1279
1870	1291
1871	1303
1872	1314
1873	1326
1874	1338
1875	1350
1876	1363
1877	1375
1878	1387
1879	1400
1880	1413
1881	1426
1882	1438
1883	1451
1884	1465
1885	1478
1886	1491
1887	1505
1888	1518
1889	1532
1890	1546
1891	1560
1892	1574
1893	1588
1894	1603
1895	1617
1896	1632
1897	1647
1898	1662
1899	1677
1900	1692
1901	1707
1902	1723
1903	1738
1904	1754
1905	1770
1906	1786
1907	1802
1908	1818
1909	1835
1910	1851
1911	1868
1912	1885
1913	1902
1914	1919
1915	1937
1916	1954
1917	1972
1918	1990
1919	2008
1920	2026
1921	2044
1922	2063
1923	2082
1924	2100
1925	2119
1926	2139
1927	2158
1928	2178
1929	2197
1930	2217
1931	2237
1932	2257
1933	2278
1934	2299
1935	2319
1936	2340
1937	2362
1938	2383
1939	2404
1940	2426
1941	2448
1942	2470
1943	2493
1944	2515
1945	2538
1946	2561
1947	2584
1948	2608
1949	2631
1950	2655
1951	2679
1952	2703
1953	2728
1954	2753
1955	2778
1956	2803
1957	2828
1958	2854
1959	2879
1960	2906
1961	2938
1962	2843
1963	2848
1964	2907
1965	3097
1966	3415
1967	3636
1968	3989
1969	4231
1970	4755
1971	4908
1972	5215
1973	5723
1974	6255
1975	7393
1976	8495
1977	9281
1978	10030
1979	10840
1980	11500
1981	11870
1982	12230
1983	12320
1984	12650
1985	13230
1986	13610
1987	14030
1988	15080
1989	16170
1990	17040
1991	17950
1992	18620
1993	19270
1994	20180
1995	21190
1996	21920
1997	22790
1998	23470
1999	24210
2000	25610
2001	25000
2002	25460
2003	25220
2004	25100
2005	25780
2006	26290
2007	27170
2008	28060
2009	27100
2010	27830
2011	28180
2012	28380
2013	29020
2014	29510
2015	29990
2016	30440
2017	30870
2018	31320
2019	31480