Year	Number of
1990	73.21
1991	75.47
1992	76.64
1993	78.83
1994	81.27
1995	82.71
1996	83.75
1997	84.51
1998	85.15
1999	87.13
2000	90.25
2001	93.15
2002	95.46
2003	97.3
2004	100.43
2005	101.86
2006	103.17
2007	106.29
2008	109.16
2009	112.69
2010	115.47
2011	118.37
2012	120.78
2013	123.74
2014	125.72
2015	128.94
2016	133.76