Year	Percent
1981	174.30685
1982	205.16223
1983	206.32886
1984	176.04228
1985	101.09005
1986	69.21542
1987	63.53516
1988	55.9663
1989	51.30493
1990	62.34138
1991	79.92977
1992	34.3136
1993	31.82688
1994	57.51856
1995	67.98931
1996	86.73453
1997	99.8303
1998	106.13596
1999	108.63414
2000	117.91536
2001	119.54716
2002	160.75402
2003	201.49502
2004	253.47508
2005	293.46304
2006	334.45987
2007	414.06724
2008	517.15393
2009	547.93525
2010	396.19397
2011	311.64441
2012	297.60779
2013	263.68044
2014	220.27364
2015	256.81474
2016	216.70009