Year	Number of
1990	150.31
1991	153.84
1992	158.02
1993	166.32
1994	171.03
1995	175.63
1996	179.18
1997	187.83
1998	204.09
1999	217.02
2000	231.93
2001	256.64
2002	276.51
2003	292.75
2004	308.59
2005	327.31
2006	344.47
2007	350.74
2008	351.99
2009	350.04
2010	352.06
2011	356.44
2012	364.37
2013	363.25
2014	365.97
2015	364.93
2016	367.41