Year	Number
1993	15.37755
1994	15.56332
1995	15.37769
1996	14.19169
1997	14.57888
1998	13.16196
1999	13.11281
2000	12.92344
2001	13.1431
2002	13.02755
2003	13.73222
2004	11.41328
2005	11.20998
2006	10.62664
2007	9.4394
2008	9.33901
2009	9.18321
2010	9.0718
2011	8.96265
2012	8.86497
2013	10.06775
2014	10.10363
2015	10.20569
2016	9.69943