Year	Number of
1990	108.51
1991	107.64
1992	109.07
1993	109.09
1994	105.02
1995	102.83
1996	104.73
1997	110.59
1998	115.56
1999	113.85
2000	118.99
2001	104.35
2002	104.34
2003	109.06
2004	119.73
2005	120.43
2006	121.18
2007	124.07
2008	129.24
2009	127.77
2010	130.76
2011	134.46
2012	136.71
2013	134.29
2014	132.7
2015	131.65
2016	122.55