Year	Number of
1990	179.73
1991	182.34
1992	188.45
1993	197.96
1994	203.02
1995	208.98
1996	219.81
1997	231.37
1998	241.07
1999	252.51
2000	268.24
2001	273.28
2002	285.26
2003	295.09
2004	308.93
2005	326.95
2006	344.5
2007	362.81
2008	378.36
2009	396
2010	416.69
2011	427.83
2012	439.69
2013	453.83
2014	467.04
2015	482.09
2016	497.64