Year	Number of
1990	357.68
1991	335.48
1992	313.06
1993	290.92
1994	271.16
1995	254.29
1996	250.07
1997	246.93
1998	244.39
1999	241.93
2000	239.29
2001	245.58
2002	251.91
2003	260.36
2004	268.9
2005	277.51
2006	279.87
2007	281.97
2008	283.96
2009	286.7
2010	290.57
2011	292.59
2012	295.75
2013	297.34
2014	298.82
2015	300.14
2016	303.36