Year	Number
1993	12.24197
1994	12.21414
1995	11.02098
1996	10.49779
1997	10.71946
1999	14.67131
2000	15.05171
2001	14.86956
2002	15.48066
2003	15.34126
2004	15.31998
2005	14.86558
2006	14.54045
2007	14.00533
2008	14.26922
2013	15.86648
2014	15.82946
2015	15.45905
2017	16.61873