Year	Number of
1990	143.36
1991	147.55
1992	151.75
1993	156.63
1994	162.08
1995	168.47
1996	174.13
1997	180.86
1998	188.89
1999	196.81
2000	202.32
2001	206.88
2002	215.48
2003	218.6
2004	222.27
2005	226.66
2006	230.22
2007	233.32
2008	238.48
2009	242.93
2010	246.84
2011	249.86
2012	254.91
2013	261.23
2014	267.13
2015	273.57
2016	279.75