Year	Number of
1990	238.54
1991	245.54
1992	253.52
1993	262.12
1994	271.04
1995	280.29
1996	287.59
1997	294.74
1998	301.9
1999	309.42
2000	317.64
2001	325.86
2002	335.12
2003	345.34
2004	356.44
2005	368.76
2006	381.67
2007	395.54
2008	411.14
2009	428.16
2010	447.26
2011	464.73
2012	484.08
2013	504.83
2014	527.08
2015	550.76
2016	574.89