Year	Number of
1990	304.92
1991	309.45
1992	318.91
1993	336.75
1994	352.99
1995	371.18
1996	371.72
1997	362.79
1998	353.85
1999	350.97
2000	355.06
2001	356.73
2002	359.52
2003	359.86
2004	363.65
2005	363.57
2006	372.36
2007	376.82
2008	388.16
2009	397.66
2010	403.41
2011	404.89
2012	406.53
2013	408.8
2014	411.35
2015	415.09
2016	419.41