Year	Number of
1990	139.7
1991	144.48
1992	149.75
1993	155.27
1994	161.15
1995	167.42
1996	172.83
1997	178.03
1998	183.74
1999	188.93
2000	194.59
2001	200.08
2002	206.13
2003	212.54
2004	219.47
2005	227.89
2006	238.11
2007	249.35
2008	261.66
2009	273.82
2010	285.82
2011	299.36
2012	313.9
2013	330.04
2014	347.73
2015	366.78
2016	386.38