Year	Number of
1990	79.68
1991	81.4
1992	83.49
1993	85.98
1994	88.41
1995	91
1996	93.16
1997	96.77
1998	100.07
1999	103.73
2000	107.95
2001	110.43
2002	113.49
2003	116.65
2004	120
2005	123.15
2006	125.8
2007	130.25
2008	133.1
2009	135.56
2010	138.52
2011	144.17
2012	146.38
2013	150.28
2014	155.24
2015	160.48
2016	165.93