Year	Percent
1979	8.09897
1980	5.89214
1981	5.83257
1982	5.66739
1983	5.04088
1984	6.44156
1985	7.36072
1986	12.05163
1987	22.60481
1988	47.90125
1989	57.68979
1990	39.48499
1991	29.61494
1992	30.75582
1993	36.13328
1994	42.09325
1995	32.71797
1996	23.26064
1997	7.51231
1998	30.62016
1999	63.08679
2000	30.49363
2001	43.88324
2002	41.1656
2003	48.41253
2004	55.99901
2005	79.94444
2006	82.46752
2007	99.99351
2008	46.97553
2009	92.53404
2010	99.76356
2011	82.84158
2012	96.45179
2013	94.55759
2014	85.93002
2015	89.03904
2016	88.67243
2017	115.74502