Year	Percent
1971	35.80923
1987	70.65414
1988	73.03027
1989	74.86692
1990	79.11038
1991	82.81575
1992	86.61359
1993	92.41663
1994	91.63503
1995	95.93658
1997	94.3911
2000	89.54463
2001	93.35199
2002	93.35639
2003	88.30375
2004	105.01328
2005	110.62552
2006	97.00108
2007	94.24286
2008	97.93828
2009	103.01048
2010	104.88285
2011	103.98018
2012	102.02608
2015	101.8182