Year	Measure
1800	517.5
1820	517.5
1913	799.5
1950	1118
1951	1145
1952	1173
1953	1200
1954	1228
1955	1256
1956	1284
1957	1313
1958	1342
1959	1370
1960	1386
1961	1381
1962	1400
1963	1427
1964	1453
1965	1456
1966	1496
1967	1508
1968	1576
1969	1621
1970	1636
1971	1650
1972	1684
1973	1671
1974	1706
1975	1752
1976	1740
1977	1783
1978	1824
1979	1868
1980	1989
1981	2257
1982	2368
1983	2462
1984	2575
1985	2719
1986	2824
1987	2603
1988	2411
1989	2131
1990	2036
1991	1903
1992	1793
1993	1689
1994	1603
1995	1614
1996	1652
1997	1694
1998	1736
1999	1771
2000	1803
2001	1857
2002	1934
2003	1967
2004	1997
2005	1995
2006	2003
2007	2004
2008	2020
2009	2002
2010	2018
2011	2049
2012	2094
2013	2153
2014	2217
2015	2287
2016	2360
2017	2435
2018	2513