Year	Number of
1990	85.97
1991	89.02
1992	92
1993	96.43
1994	100.89
1995	105.47
1996	109.86
1997	114
1998	118.04
1999	121.55
2000	123.03
2001	127.53
2002	128.5
2003	130.38
2004	132.74
2005	132.75
2006	133.9
2007	137.51
2008	146.35
2009	153.72
2010	159.32
2011	160.91
2012	161.76
2013	162.27
2014	163.43
2015	166.4
2016	168.76