Year	Number of
1990	86.05
1991	95.61
1992	104.01
1993	114.67
1994	126.28
1995	140.35
1996	153.72
1997	166.35
1998	180.82
1999	195.23
2000	213.12
2001	227.76
2002	242.22
2003	258.6
2004	265.47
2005	272.63
2006	277.21
2007	279.55
2008	279.05
2009	279.62
2010	282.33
2011	282.65
2012	278.39
2013	276.39
2014	275.63
2015	274.36
2016	275.28