Year	Percent
1981	61.18317
1982	51.77362
1983	74.79885
1984	56.95832
1985	77.41604
1986	53.58379
1987	56.71724
1988	65.36714
1989	102.18184
1990	108.73295
1991	115.42122
1992	150.43498
1993	320.99345
1994	247.08445
1995	240.97395
1996	303.56869
1997	93.22535
1998	132.41569
1999	176.76532
2000	120.64837
2001	128.23424
2002	124.72391
2003	145.92626
2004	145.59052
2005	125.76631
2006	144.80269
2007	168.06712
2008	81.98789
2009	142.99557
2010	160.2598
2011	132.78108
2012	148.38535
2013	154.78588
2014	135.77522
2015	129.19457
2016	121.33042
2017	144.91958