Year	Measure
1820	898.3
1821	908.8
1822	919.5
1823	930.3
1824	941.2
1825	952.3
1826	963.5
1827	974.8
1828	986.2
1829	997.8
1830	1010
1831	1021
1832	1033
1833	1045
1834	1058
1835	1070
1836	1083
1837	1095
1838	1108
1839	1121
1840	1134
1841	1148
1842	1161
1843	1175
1844	1189
1845	1203
1846	1217
1847	1231
1848	1245
1849	1260
1850	1275
1851	1290
1852	1305
1853	1320
1854	1336
1855	1352
1856	1367
1857	1383
1858	1400
1859	1416
1860	1433
1861	1450
1862	1467
1863	1484
1864	1501
1865	1519
1866	1537
1867	1555
1868	1573
1869	1591
1870	1610
1871	1629
1872	1648
1873	1667
1874	1687
1875	1707
1876	1727
1877	1747
1878	1768
1879	1788
1880	1809
1881	1831
1882	1852
1883	1874
1884	1896
1885	1918
1886	1941
1887	1963
1888	1986
1889	2010
1890	2033
1891	2057
1892	2081
1893	2106
1894	2131
1895	2156
1896	2181
1897	2206
1898	2232
1899	2259
1900	2285
1901	2312
1902	2339
1903	2367
1904	2394
1905	2422
1906	2451
1907	2480
1908	2509
1909	2538
1910	2568
1911	2598
1912	2629
1913	2659
1914	2683
1915	2707
1916	2731
1917	2756
1918	2780
1919	2805
1920	2830
1921	2855
1922	2881
1923	2906
1924	2932
1925	2958
1926	2985
1927	3011
1928	3038
1929	3065
1930	3092
1931	3120
1932	3148
1933	3176
1934	3204
1935	3233
1936	3262
1937	3291
1938	3320
1939	3349
1940	3379
1941	3409
1942	3440
1943	3470
1944	3501
1945	3533
1946	3564
1947	3596
1948	3628
1949	3660
1950	3693
1951	3838
1952	3989
1953	4147
1954	4310
1955	4479
1956	4656
1957	4839
1958	5030
1959	5228
1960	5434
1961	5648
1962	5870
1963	6101
1964	6342
1965	6591
1966	6851
1967	7121
1968	7401
1969	7692
1970	7995
1971	9010
1972	9640
1973	9919
1974	9721
1975	8160
1976	9711
1977	11250
1978	12060
1979	13160
1980	13790
1981	14030
1982	14750
1983	15330
1984	16460
1985	17030
1986	17470
1987	18500
1988	19820
1989	21120
1990	22220
1991	21790
1992	23220
1993	22810
1994	23640
1995	25510
1996	25580
1997	25800
1998	26770
1999	27760
2000	28850
2001	29670
2002	29940
2003	30050
2004	30610
2005	30940
2006	31630
2007	32450
2008	32750
2009	31270
2010	30900
2011	30260
2012	29200
2013	27140
2014	25580
2015	25530
2016	25750
2017	26110
2018	26460
2019	26750