Year	Number of
1990	144.29
1991	150.86
1992	156.45
1993	161.55
1994	167.44
1995	175.19
1996	179.33
1997	185.55
1998	193.45
1999	202.29
2000	211.61
2001	209.38
2002	207.02
2003	204.75
2004	202.13
2005	199.35
2006	199.9
2007	200.04
2008	200.94
2009	201.91
2010	203.09
2011	207.88
2012	213.24
2013	219.06
2014	225.51
2015	232.63
2016	238.8