Year	Percent
1977	20.5105
1978	22.01727
1979	22.23256
1980	19.80954
1981	30.71332
1982	37.80612
1983	45.9622
1984	39.53161
1985	36.78001
1986	35.87939
1987	38.55519
1988	39.44221
1989	35.55238
1990	42.40253
1991	42.36698
1992	38.48162
1993	49.55928
1994	41.18218
1995	38.98359
1996	40.02516
1997	31.08466
1998	40.73188
1999	30.26051
2000	41.00793
2001	49.1971
2002	75.51341
2003	68.28111
2004	80.45977
2005	61.22714
2006	74.43643
2007	74.38854
2008	74.67765
2009	85.0767
2010	82.91797
2011	77.39371
2012	83.11431
2013	75.34299
2014	75.53612
2015	72.1606
2016	132.21436