Year number of cases 2008 18660000 2009 4031000 2010 15920000 2011 4490000 2012 5731000 2013 5924000 2014 3612000 2015 3602000 2016 7434000 2017 4463000 2018 4033000 2019 4034000 2020 5074000 2021 6037000 2022 3632000 2023 4702000