Year	Number of
1990	115.49
1991	117.17
1992	118.9
1993	120.41
1994	121.9
1995	123.86
1996	130.99
1997	138.68
1998	146.81
1999	155.5
2000	164.79
2001	168.94
2002	173.04
2003	177.23
2004	181.93
2005	187.59
2006	190.56
2007	193.07
2008	195.53
2009	198
2010	200.67
2011	203.78
2012	206.91
2013	209.78
2014	212.88
2015	215.89
2016	219.47