Year	Number of
1990	244.1
1991	249.19
1992	254.39
1993	259.33
1994	264.61
1995	271.06
1996	265.35
1997	259.62
1998	254.06
1999	248.79
2000	244.15
2001	246.35
2002	248.4
2003	250.29
2004	252.53
2005	255.69
2006	268.08
2007	281.01
2008	294.75
2009	309.3
2010	325.19
2011	335.5
2012	345.57
2013	355.64
2014	366.67
2015	377.55
2016	389.81