Year	Number of
1990	256.89
1991	264.85
1992	273.96
1993	284.21
1994	295.35
1995	307.54
1996	314.24
1997	321.38
1998	329.52
1999	338.36
2000	348.13
2001	360.06
2002	372.92
2003	387.63
2004	403.17
2005	419.65
2006	435.92
2007	452.88
2008	472.03
2009	492.48
2010	514.49
2011	532.55
2012	551.9
2013	572.66
2014	595.07
2015	619.19
2016	644.86