Year	Number of
1990	214.92
1991	221.85
1992	228.83
1993	234.88
1994	240.89
1995	248.51
1996	254.29
1997	261.34
1998	268.73
1999	276.32
2000	284.7
2001	293.39
2002	303.48
2003	313.79
2004	324.47
2005	335.77
2006	346.4
2007	355.93
2008	364.35
2009	374.48
2010	385.31
2011	397.11
2012	409.35
2013	421.65
2014	434.1
2015	447.08
2016	462.37