Year	Measure
1820	989.4
1821	994.1
1822	998.7
1823	1003
1824	1008
1825	1013
1826	1018
1827	1022
1828	1027
1829	1032
1830	1037
1831	1042
1832	1047
1833	1051
1834	1056
1835	1061
1836	1066
1837	1071
1838	1076
1839	1081
1840	1086
1841	1092
1842	1097
1843	1102
1844	1107
1845	1112
1846	1117
1847	1123
1848	1128
1849	1133
1850	1139
1851	1144
1852	1149
1853	1155
1854	1160
1855	1165
1856	1171
1857	1176
1858	1182
1859	1187
1860	1193
1861	1199
1862	1204
1863	1210
1864	1216
1865	1221
1866	1227
1867	1233
1868	1239
1869	1244
1870	1250
1871	1256
1872	1262
1873	1268
1874	1274
1875	1280
1876	1286
1877	1292
1878	1298
1879	1304
1880	1310
1881	1316
1882	1322
1883	1329
1884	1335
1885	1341
1886	1347
1887	1354
1888	1360
1889	1366
1890	1373
1891	1379
1892	1386
1893	1392
1894	1399
1895	1405
1896	1412
1897	1419
1898	1425
1899	1432
1900	1439
1901	1445
1902	1452
1903	1459
1904	1466
1905	1473
1906	1480
1907	1486
1908	1493
1909	1500
1910	1507
1911	1515
1912	1522
1913	1529
1914	1547
1915	1566
1916	1586
1917	1605
1918	1625
1919	1645
1920	1665
1921	1685
1922	1706
1923	1727
1924	1748
1925	1769
1926	1791
1927	1813
1928	1835
1929	1857
1930	1880
1931	1903
1932	1926
1933	1950
1934	1974
1935	1998
1936	2022
1937	2047
1938	2072
1939	2098
1940	2123
1941	2149
1942	2176
1943	2202
1944	2229
1945	2256
1946	2284
1947	2312
1948	2340
1949	2369
1950	2398
1951	2447
1952	2435
1953	2437
1954	2491
1955	2491
1956	2498
1957	2517
1958	2513
1959	2586
1960	2674
1961	3196
1962	3129
1963	3495
1964	3162
1965	3180
1966	2993
1967	3063
1968	2800
1969	2895
1970	2837
1971	2935
1972	3187
1973	3544
1974	3872
1975	3823
1976	4383
1977	4592
1978	4684
1979	4761
1980	4206
1981	4383
1982	4564
1983	4535
1984	4702
1985	4982
1986	5427
1987	5919
1988	6264
1989	6477
1990	6865
1991	7229
1992	7497
1993	7917
1994	8188
1995	8394
1996	8747
1997	9189
1998	9657
1999	10080
2000	10260
2001	10890
2002	11160
2003	11840
2004	12290
2005	12570
2006	13030
2007	13670
2008	14380
2009	14700
2010	15240
2011	15760
2012	16190
2013	16600
2014	17130
2015	17730
2016	18390
2017	19060
2018	19740
2019	20450