Year	Number
2005	3.950244193094839
2006	3.48102020336705
2007	4.1072420235259015
2008	3.6852492294836816
2009	5.343125403560223
2010	5.206888424259848
2011	3.886675522425492
2012	2.818775843838243
2013	3.199582316477266
2014	3.237810379393992
2015	2.8163512725316915
2016	2.999792044577868
2017	4.692844805791331
2018	3.1168835818124485
2019	4.52133143903791
2020	5.307574758951052
2021	4.0898841404552595
2022	2.0095548628054543
2023	3.160191220176838