Year	Number
1986	18.37129
1987	19.4186
1989	20.96535
1990	20
1991	15.78235
1992	16.66667
1993	14.72903
1994	12.32836
1997	11.83333
1999	11.95289
2000	13.19385
2001	11.80939
2002	11.70195
2003	11.48397
2004	11.50291
2005	11.50279
2006	11.0843
2007	10.83286
2008	10.75346
2009	10.84615
2010	10.1213
2011	10.37273
2012	10.24412
2013	9.8029
2014	10.22881
2016	5.93924