Year	Number
1996	30.5
1998	25.8706474304199
2000	15.9203977584839
2002	10.945273399353
2003	9.95024871826172
2004	6.25
2005	5.28846168518066
2006	7.21153831481934
2007	7.21153831481934
2008	7.692307472229
2009	7.5829381942749
2010	8.05687236785889
2011	7.98122072219849
2012	7.51173686981201
2013	9.85915470123291
2014	13.7931032180786
2015	15.7635469436646
2016	14.7783250808716
2017	14.7783250808716
2018	16.990291595459
2019	16.425121307373
2020	17.8743953704834
2021	18.3574886322021
2022	18.8405799865723