Year	Percent
1977	52.00523
1980	58.27309
1981	87.09807
1982	112.67493
1983	114.2575
1984	111.79862
1985	100.9058
1987	53.9152
1988	67.04413
1990	73.91424
1999	47.51195
2002	54.51572
2003	55.35852
2004	70.16129
2005	74.08577
2007	71.23596
2008	73.6101
2009	81.18508
2010	81.18563
2011	107.22971
2013	95.89775
2014	86.96952
2016	79.40231
2017	86.72137