Year	Number of
1990	73.49
1991	76.15
1992	79.22
1993	82.36
1994	86.33
1995	90.79
1996	94.96
1997	97.79
1998	101.14
1999	101.37
2000	102.03
2001	102.27
2002	102.16
2003	102.52
2004	104.35
2005	105.6
2006	106.52
2007	107.85
2008	109.79
2009	112.14
2010	114.57
2011	116.43
2012	119.1
2013	122.02
2014	125.14
2015	128.61
2016	132.14