Year	% of total
1971	93.22136076235334
1972	93.89926325069791
1973	95.04270211841026
1974	94.40536864376368
1975	94.27678213080179
1976	94.17487666291721
1977	94.91412219506373
1978	95.19678329987484
1979	95.87799883473576
1980	95.84135090140119
1981	96.03599650945594
1982	95.66768621848726
1983	95.75782822911697
1984	95.55581396889276
1985	95.67720015107224
1986	95.54890361502163
1987	95.2455616180798
1988	95.65329128593284
1989	95.22254796393959
1990	78.32422445722342
1991	93.78304837999835
1992	94.27459010559534
1993	94.26527032877513
1994	94.12479015265473
1995	94.37856993531008
1996	94.91917316801829
1997	94.56333523298791
1998	95.53296223711874
1999	95.901121394169
2000	94.64854451206615
2001	95.62352156686828
2002	96.39054312057218
2003	96.79430727154322
2004	86.56211106183967
2005	87.54199013046605
2006	88.48887803031846
2007	88.89179661713597
2008	97.0107512314506
2009	96.79487150862236
2010	97.33297609486344
2011	97.17518203742311
2012	96.93591365843342
2013	96.94117852193088
2014	96.90434258307592