Year	Measure
1971	7753.32429
1972	7800.99438
1973	10071.44213
1974	8008.83516
1975	12413.72641
1976	8790.88336
1977	9513.89749
1978	8442.317
1979	13717.73828
1980	14799.60675
1981	16709.53156
1982	17338.6963
1983	16047.85462
1984	16474.84734
1985	15217.33799
1986	15073.61559
1987	14647.59756
1988	14576.09161
1989	14350.31286
1990	13698.28627
1991	14814.29196
1992	15239.44688
1993	15621.9979
1994	15509.50019
1995	15870.8397
1996	16555.07138
1997	19031.75411
1998	19388.47992
1999	19875.20876
2000	18438.15036
2001	19562.26434
2002	21142.15244
2003	20523.32316
2004	21959.43626
2005	19268.69458
2006	19389.46557
2007	18607.43355
2008	16371.35277
2009	15233.91921
2010	15531.77601
2011	16030.60725
2012	18055.61139
2013	17926.71807
2014	18562.66691