Year	Number of
1990	95.88
1991	97.99
1992	101.51
1993	103.95
1994	106.93
1995	112.08
1996	116.22
1997	120.4
1998	125.1
1999	129.84
2000	134.41
2001	138.89
2002	143.52
2003	149.03
2004	154.37
2005	159.78
2006	165.11
2007	170.47
2008	176.35
2009	182.49
2010	188.85
2011	194.9
2012	201.35
2013	207.97
2014	214.93
2015	222.26
2016	229.48