Year	Number of
1990	43.75
1991	45.98
1992	46.45
1993	46.89
1994	46.67
1995	45.15
1996	45.08
1997	47.77
1998	49.93
1999	51.92
2000	55.76
2001	59.24
2002	61.23
2003	62.63
2004	66.43
2005	69.37
2006	68.91
2007	74.45
2008	78.75
2009	82.42
2010	83.88
2011	89.13
2012	90.19
2013	92.54
2014	90.31
2015	90.56
2016	91.15