Year	Number of
1990	153.54
1991	165
1992	176.99
1993	189.86
1994	203.59
1995	218.42
1996	234.18
1997	251.14
1998	270.25
1999	291.28
2000	314.82
2001	341.84
2002	372.84
2003	408.04
2004	446.99
2005	491.33
2006	542.8
2007	598.79
2008	660.11
2009	728.83
2010	806.88
2011	892.12
2012	989.79
2013	1098.63
2014	1221.77
2015	1359.05
2016	1507.45