Year	Number of
1990	105.96
1991	113.05
1992	120.74
1993	129.16
1994	138.24
1995	148.06
1996	153.92
1997	160.09
1998	166.86
1999	173.87
2000	181.16
2001	183.25
2002	185.37
2003	187.94
2004	190.64
2005	193.54
2006	195.46
2007	197.62
2008	200.4
2009	203.43
2010	206.76
2011	210.16
2012	213.98
2013	218.05
2014	222.46
2015	227.16
2016	232.98