Year	Number of
1990	199.75
1991	203.54
1992	207.3
1993	217.14
1994	228.1
1995	237.74
1996	246.74
1997	247.24
1998	249.71
1999	249.04
2000	249.13
2001	249.18
2002	248.11
2003	251.49
2004	254.16
2005	255.18
2006	255.12
2007	253.6
2008	252.57
2009	251.62
2010	250.97
2011	249.55
2012	249.39
2013	249.82
2014	250.14
2015	251.04
2016	252.47