Year	Number of
1990	210.93
1991	201.62
1992	188.41
1993	183.3
1994	185.55
1995	200.57
1996	206.73
1997	219.48
1998	234.7
1999	248.93
2000	271.3
2001	297.37
2002	333.13
2003	353.84
2004	377.67
2005	385.51
2006	387.99
2007	389.11
2008	389.56
2009	387.37
2010	387.67
2011	387.43
2012	389.27
2013	395.18
2014	402.43
2015	413.77
2016	427.03