Year	Percent
1988	46.88086
1991	52.43548
1992	57.59571
1999	64.53402
2000	67.28977
2001	67.04637
2002	72.10893
2003	73.09776
2004	73.33084
2005	76.83591
2006	77.84516
2008	79.29437
2012	102.13207
2013	101.78421
2014	103.7804
2015	105.3747
2016	109.77561
2017	112.75775