Year	Number of
1990	451.47
1991	438.38
1992	411.14
1993	378.95
1994	388.1
1995	378.41
1996	369.52
1997	365.18
1998	362
1999	368.93
2000	376.03
2001	385.79
2002	391.33
2003	397.26
2004	399.28
2005	399.7
2006	388.53
2007	378.17
2008	374.62
2009	379.03
2010	396.83
2011	422.63
2012	404.1
2013	387.94
2014	389.54
2015	395.91
2016	401.26