Year	Number of
1990	116.33
1991	120.37
1992	119.62
1993	122.28
1994	125.35
1995	124.73
1996	124.38
1997	124.83
1998	125.26
1999	127.54
2000	131.72
2001	139.3
2002	146.21
2003	153.09
2004	164.23
2005	172.08
2006	173.3
2007	184.71
2008	193.94
2009	207.04
2010	216.65
2011	218.74
2012	220.47
2013	224.87
2014	224.84
2015	224.76
2016	226.43