Year	Number
2007	2.526152549029085
2008	1.180339927523329
2009	2.3408026361244096
2010	2.376093280325336
2011	1.5022731470684927
2012	1.8969881661997496
2013	2.3865387610644455
2014	2.656617886870462
2015	3.0927796194640362
2016	3.1626482277259473
2017	3.633751943457332
2018	3.6439092813288476
2019	4.728273321551848
2020	8.09818883631141
2021	6.045938872554393
2022	5.014569987948403
2023	3.4076053894117946