Year	Measure
1800	400.7
1820	400.7
1913	619.1
1950	1128
1951	1153
1952	1179
1953	1203
1954	1229
1955	1256
1956	1282
1957	1308
1958	1336
1959	1361
1960	1349
1961	1343
1962	1390
1963	1345
1964	1286
1965	1264
1966	1215
1967	1197
1968	1166
1969	1219
1970	1216
1971	1212
1972	1104
1973	1026
1974	1141
1975	1306
1976	1256
1977	1134
1978	1101
1979	855.8
1980	804.7
1981	794.8
1982	797.9
1983	886.9
1984	896.3
1985	1083
1986	1011
1987	952.4
1988	1066
1989	1098
1990	999.1
1991	1066
1992	1058
1993	1004
1994	1023
1995	996
1996	995.1
1997	1005
1998	1049
1999	1039
2000	1017
2001	1084
2002	1156
2003	1287
2004	1669
2005	1749
2006	1709
2007	1670
2008	1656
2009	1597
2010	1760
2011	1726
2012	1769
2013	1865
2014	2011
2015	2122
2016	2140
2017	2154
2018	2152