Year	Measure
1800	1069
1820	1092
1885	1645
1886	1582
1887	1849
1888	1779
1889	1654
1890	1647
1891	1509
1892	1652
1893	1872
1894	2129
1895	1970
1896	2169
1897	2133
1898	2190
1899	2324
1900	2274
1901	2331
1902	2532
1903	2358
1904	2607
1905	2308
1906	2206
1907	2119
1908	2315
1909	2403
1910	2564
1911	2369
1912	2560
1913	2689
1914	2568
1915	2643
1916	2350
1917	2063
1918	1263
1919	1089
1920	1093
1921	1001
1922	1162
1923	1338
1924	1695
1925	2118
1926	2378
1927	2477
1928	2605
1929	2636
1930	2755
1931	2780
1932	2737
1933	2840
1934	3100
1935	3545
1936	3786
1937	4100
1938	4088
1939	4254
1940	4077
1946	3639
1947	4043
1948	4568
1949	4989
1950	5404
1951	5336
1952	5585
1953	5729
1954	5907
1955	6300
1956	6782
1957	6800
1958	7183
1959	6978
1960	7503
1961	7793
1962	7874
1963	7579
1964	8442
1965	8812
1966	9136
1967	9439
1968	9893
1969	9937
1970	10600
1971	10780
1972	10730
1973	11520
1974	11750
1975	11670
1976	12110
1977	12280
1978	12480
1979	12320
1980	12240
1981	12250
1982	12450
1983	12740
1984	12780
1985	12780
1986	13190
1987	13250
1988	13430
1989	13560
1990	13150
1991	12370
1992	9744
1993	8190
1994	7406
1995	7804
1996	8183
1997	8765
1998	9413
1999	9260
2000	9632
2001	10270
2002	11010
2003	12120
2004	13050
2005	14080
2006	15280
2007	16860
2008	17450
2009	14940
2010	15410
2011	17690
2012	18470
2013	19160
2014	19900
2015	20700
2016	21570
2017	22500
2018	23470