Year	Measure
1800	505.1
1820	505.1
1913	780.5
1950	943.1
1951	953
1952	911.3
1953	1010
1954	1108
1955	1009
1956	1039
1957	1044
1958	998
1959	1111
1960	1159
1961	1167
1962	1190
1963	1198
1964	1189
1965	1171
1966	1139
1967	1126
1968	1108
1969	1114
1970	1197
1971	1253
1972	1178
1973	1175
1974	1223
1975	1048
1976	990.2
1977	993.2
1978	1059
1979	1017
1980	972.8
1981	960.2
1982	876
1983	784.5
1984	807.3
1985	822.8
1986	831.2
1987	847
1988	870.1
1989	889.4
1990	893.8
1991	915.1
1992	925.1
1993	942
1994	945.6
1995	961.4
1996	984.9
1997	1005
1998	1030
1999	1052
2000	1068
2001	1088
2002	1112
2003	1144
2004	1182
2005	1225
2006	1268
2007	1316
2008	1391
2009	1411
2010	1486
2011	1657
2012	1728
2013	1802
2014	1877
2015	1953
2016	2013
2017	2073
2018	2138