Year	Number
1992	11.97474
1993	12.57397
1994	11.04919
2000	11.3412
2001	11.34131
2002	11.68658
2003	11.947
2004	12.13805
2005	12.65189
2006	13.05043
2007	13.22193
2008	12.70941
2009	12.36287
2010	12.59613
2011	13.31491
2012	13.35461
2015	13.46366
2016	12.87062
2017	12.74128