Year	Measure
1800	1094
1820	1117
1870	2196
1890	2939
1900	3338
1910	3916
1913	4107
1926	2966
1927	2928
1928	2889
1929	2718
1930	2875
1931	2899
1932	2700
1933	2794
1934	2788
1935	2822
1936	2817
1937	2667
1938	2930
1948	1926
1950	2788
1951	2962
1952	3145
1953	3329
1954	3529
1955	3722
1956	3829
1957	3943
1958	4066
1959	4206
1960	4349
1961	4602
1962	4735
1963	5040
1964	5327
1965	5629
1966	6234
1967	6471
1968	6461
1969	6661
1970	6730
1971	7598
1972	8011
1973	8201
1974	8579
1975	8873
1976	9239
1977	9356
1978	9584
1979	9785
1980	9755
1981	9640
1982	9605
1983	9498
1984	9855
1985	9810
1986	9943
1987	9696
1988	9637
1989	9296
1990	8282
1991	7226
1992	6598
1993	6706
1994	6976
1995	7487
1996	7801
1997	7347
1998	7008
1999	6935
2000	7090
2001	7502
2002	7885
2003	8281
2004	8994
2005	9374
2006	10130
2007	10780
2008	11590
2009	10840
2010	10740
2011	11000
2012	11060
2013	11260
2014	11500
2015	11790
2016	12150
2017	12580
2018	13050