Year	Number of
1990	205.14
1991	211.72
1992	223.17
1993	235.17
1994	250.46
1995	268.52
1996	284.01
1997	300.54
1998	315.47
1999	328.03
2000	336.69
2001	336.91
2002	334.13
2003	332.91
2004	320.63
2005	309.58
2006	327.89
2007	340.62
2008	352.76
2009	366.63
2010	368.92
2011	377.76
2012	389.15
2013	400.61
2014	413.18
2015	425.38
2016	437.61