Year	Number of
1990	271.23
1991	278.74
1992	287.04
1993	295.79
1994	305.18
1995	314.07
1996	323.95
1997	332.71
1998	340.83
1999	331.86
2000	327.33
2001	324.04
2002	321.28
2003	326.08
2004	325.48
2005	329.03
2006	332.97
2007	338.35
2008	348.18
2009	354.98
2010	363.95
2011	374.34
2012	385.14
2013	397.67
2014	411.53
2015	425.21
2016	440.06