Year	Number of
1990	95.09
1991	99
1992	103.13
1993	107.64
1994	112.46
1995	117.7
1996	121.74
1997	126.13
1998	130.46
1999	134.85
2000	139.33
2001	141.17
2002	143.02
2003	144.86
2004	146.69
2005	148.59
2006	152.94
2007	157.55
2008	162.44
2009	167.47
2010	172.66
2011	176.71
2012	180.9
2013	185.1
2014	189.34
2015	193.69
2016	198.23