Year	Percent
1981	85.78681
1983	90.04899
1984	90.78701
1985	89.17316
1986	86.95142
1987	86.2511
1988	85.63164
1989	87.13304
1990	89.23535
1998	84.64189
1999	86.40971
2001	100.3428
2002	94.39285
2003	94.94994
2004	93.66018
2005	93.48595
2006	91.07643
2007	90.89815
2008	91.83446
2009	91.61971
2013	99.4954
2015	101.34768