Year	Measure
1800	340
1820	340
1821	341.4
1822	342.8
1823	344.2
1824	345.6
1825	347.1
1826	348.5
1827	349.9
1828	351.4
1829	352.8
1830	354.3
1831	355.7
1832	357.2
1833	358.6
1834	360.1
1835	361.6
1836	363.1
1837	364.6
1838	366.1
1839	367.6
1840	369.1
1841	370.6
1842	372.2
1843	373.7
1844	375.2
1845	376.8
1846	378.3
1847	379.9
1848	381.4
1849	383
1850	384.6
1851	386.2
1852	387.8
1853	389.4
1854	391
1855	392.6
1856	394.2
1857	395.8
1858	397.4
1859	399.1
1860	400.7
1861	402.4
1862	404
1863	405.7
1864	407.4
1865	409
1866	410.7
1867	412.4
1868	414.1
1869	415.8
1870	417.5
1871	419.2
1872	421
1873	422.7
1874	424.4
1875	426.2
1876	427.9
1877	429.7
1878	431.5
1879	433.2
1880	435
1881	436.8
1882	438.6
1883	440.4
1884	442.2
1885	444
1886	445.9
1887	447.7
1888	449.6
1889	451.4
1890	453.3
1891	455.1
1892	457
1893	458.9
1894	460.8
1895	462.7
1896	464.6
1897	466.5
1898	468.4
1899	470.3
1900	472.3
1901	474.2
1902	476.2
1903	478.1
1904	480.1
1905	482.1
1906	484
1907	486
1908	488
1909	490.1
1910	492.1
1911	494.1
1912	496.1
1913	498.2
1914	500.2
1915	502.3
1916	504.3
1917	506.4
1918	508.5
1919	510.6
1920	512.7
1921	514.8
1922	516.9
1923	519.1
1924	521.2
1925	523.3
1926	525.5
1927	527.7
1928	529.8
1929	532
1930	534.2
1931	536.4
1932	538.6
1933	540.8
1934	543
1935	545.3
1936	547.5
1937	549.8
1938	552
1939	554.3
1940	556.6
1941	558.9
1942	561.2
1943	563.5
1944	565.8
1945	568.1
1946	570.5
1947	572.8
1948	575.2
1949	577.6
1950	579.9
1951	587.3
1952	594.7
1953	602.3
1954	593.9
1955	596.8
1956	604.3
1957	583.6
1958	578.7
1959	627.1
1960	654.6
1961	676.7
1962	695.8
1963	712.8
1964	727.6
1965	741.2
1966	754.2
1967	765.8
1968	776.9
1969	787.7
1970	798.3
1971	730.5
1972	691.5
1973	682.1
1974	660.1
1975	676.8
1976	671.1
1977	667.8
1978	730.7
1979	801.8
1980	1084
1981	1166
1982	1181
1983	1274
1984	1302
1985	1392
1986	1408
1987	1481
1988	1501
1989	1555
1990	1588
1993	1525
1994	1600
1995	1700
1996	1789
1997	1903
1998	2019
1999	2169
2000	2291
2001	2407
2002	2505
2003	2601
2004	2693
2005	2831
2006	3072
2007	3289
2008	3445
2009	3523
2010	3656
2011	3788
2012	3896
2013	4001
2014	4125
2015	4260
2016	4412
2017	4570
2018	4734