Year	Measure
1800	671.5
1820	701
1821	707.4
1822	728.1
1823	752.8
1824	794.9
1825	833.2
1826	849
1827	874.8
1828	896.8
1829	946.6
1830	1148
1831	1187
1832	1213
1833	1218
1834	1281
1835	1550
1836	1523
1837	1597
1838	1577
1839	1471
1840	1859
1841	1586
1842	1447
1843	1677
1844	1907
1845	1962
1846	2168
1847	2508
1848	2870
1849	2836
1850	2673
1851	3173
1852	3721
1853	4074
1854	3567
1855	3386
1856	4131
1857	3646
1858	3109
1859	4014
1860	3917
1861	3858
1862	3708
1863	3695
1864	3919
1865	3738
1866	3848
1867	4207
1868	4272
1869	4187
1870	4430
1871	4464
1872	4809
1873	5175
1874	5190
1875	5601
1876	5424
1877	5463
1878	5789
1879	5691
1880	5800
1881	6029
1882	5498
1883	6057
1884	5825
1885	5985
1886	5860
1887	6269
1888	6096
1889	6425
1890	6033
1891	6316
1892	5408
1893	5018
1894	5096
1895	4720
1896	4987
1897	4629
1898	5267
1899	5197
1900	5432
1901	5195
1902	5174
1903	5517
1904	5813
1905	5795
1906	6100
1907	6248
1908	6352
1909	6741
1910	7051
1911	6908
1912	6900
1913	6979
1914	6803
1915	6627
1916	6602
1917	6484
1918	6228
1919	6382
1920	6450
1921	6647
1922	6853
1923	7027
1924	7332
1925	7516
1926	7542
1927	7503
1928	7379
1929	7123
1930	6372
1931	5892
1932	6177
1933	6554
1934	6848
1935	7197
1936	7465
1937	7776
1938	7967
1939	7912
1940	8345
1941	9187
1942	10160
1943	10430
1944	9964
1945	9362
1946	8926
1947	9020
1948	9430
1949	9795
1950	10030
1951	10160
1952	10040
1953	10160
1954	10540
1955	10860
1956	10970
1957	10950
1958	11240
1959	11680
1960	11900
1961	11710
1962	12220
1963	12720
1964	13330
1965	13740
1966	13860
1967	14530
1968	15090
1969	15650
1970	16270
1971	16630
1972	16790
1973	17430
1974	17570
1975	17820
1976	18350
1977	18330
1978	18640
1979	19380
1980	19510
1981	19840
1982	19480
1983	19210
1984	20300
1985	21040
1986	21170
1987	21890
1988	22510
1989	23130
1990	23150
1991	22890
1992	23420
1993	24050
1994	24780
1995	25520
1996	26150
1997	27000
1998	28170
1999	28980
2000	29240
2001	30040
2002	30690
2003	31630
2004	32100
2005	32800
2006	33200
2007	34200
2008	34440
2009	34390
2010	34880
2011	35250
2012	36060
2013	36670
2014	37420
2015	38080
2016	38770
2017	39520
2018	40300