Year	Number
1993	17.67472
1994	18.04931
1995	18.29626
1996	18.57341
2008	12.6773
2009	12.55378
2010	12.31476
2011	12.19469
2012	10.42194
2013	9.9993
2014	9.43018
2015	8.80186
2016	8.82475
2017	9.6802