Year	Percent
1988	41.99126
1990	43.29166
1992	40.38053
1993	43.43504
1994	48.53837
1996	56.58013
1997	59.51012
1998	63.65893
1999	68.93505
2000	67.27818
2001	67.37724
2002	67.7739
2003	67.23237
2004	67.57173
2005	69.91735
2006	73.74953
2007	76.29671
2008	78.64609
2009	81.70917
2010	85.72018
2011	91.57357
2012	95.28582
2013	99.71284
2014	101.32902
2015	101.65508
2016	100.37615