Year	Number
1996	27.5
1998	23.8805961608887
2000	27.3631839752197
2002	30.8457717895508
2003	29.8507461547852
2004	26.9230766296387
2005	26.4423084259033
2006	33.1730766296387
2007	34.1346168518066
2008	34.6153831481934
2009	31.7535552978516
2010	33.6492881774902
2011	35.6807518005371
2012	37.0892028808594
2013	38.4976539611816
2014	37.4384231567383
2015	37.9310340881348
2016	32.019702911377
2017	32.019702911377
2018	30.5825233459473
2019	31.8840579986572
2020	29.9516906738281
2021	32.8502426147461
2022	38.164249420166