Year per 1,000 population at risk 2000 9.00495061657992 2001 9.90228903313973 2002 12.0120355081582 2003 10.306246193894 2004 10.5322276838574 2005 9.78135017982618 2006 7.18169415280518 2007 5.57575975546528 2008 4.82662236488233 2009 4.56699674960781 2010 3.29671784635223 2011 2.67100398188962 2012 3.46075398683789 2013 5.31181360432519 2014 7.04053693824214 2015 7.20387856769027 2016 5.95663456199076 2017 5.86077753261201 2018 4.62152548527599 2019 3.54700312403722 2020 2.27394783565958 2021 1.75576540497239 2022 2.67248601618327