100.0
CO
1990
97.1
CO
1991
93.0
CO
1992
88.8
CO
1993
81.2
CO
1994
77.4
CO
1995
74.8
CO
1996
68.8
CO
1997
64.4
CO
1998
59.5
CO
1999
53.7
CO
2000
50.1
CO
2001
46.0
CO
2002
42.5
CO
2003
39.4
CO
2004
34.7
CO
2005
31.7
CO
2006
28.5
CO
2007
25.6
CO
2008
23.4
CO
2009
21.0
CO
2010
19.5
CO
2011
17.9
CO
2012
16.4
CO
2013
15.3
CO
2014
14.8
CO
2015