Year	Number of
1990	84.31
1991	88.44
1992	95.56
1993	100.99
1994	108.89
1995	113.93
1996	122.33
1997	131.32
1998	135.68
1999	140.35
2000	144
2001	147.88
2002	154.28
2003	162.02
2004	168.46
2005	173.96
2006	180.73
2007	186.48
2008	191.51
2009	196.56
2010	203.07
2011	208.05
2012	217.1
2013	227.57
2014	233.86
2015	239.84
2016	246.4