Year	% of total
1985	90.96025325360534
1986	92.61829652996846
1987	93.16213795162736
1988	92.86117381489842
1989	93.56379988757729
1990	92.1146953405018
1991	92.16475689067822
1992	94.63980880846705
1993	91.36328427575523
1994	94.40147329650092
1995	95.70015220700152
1996	95.4858454475899
1997	95.49211119459054
1998	95.66355140186916
1999	96.30541871921181
2000	97.01289884589274
2001	96.75174013921114
2002	97.17223650385604
2003	96.84512428298278
2004	96.60914320314865
2005	96.95817490494296
2006	96.78329571106094
2007	95.94704134017833
2008	96.00099975006249
2009	96.23669225055707
2010	95.84975654996522
2011	94.79717813051145
2012	94.74667774086379
2013	92.94820717131475
2014	92.33630952380952
2015	92.74442227462362