| Year | |
|---|---|
| 1997 | 241.9 |
| 1998 | 274.1 |
| 1999 | 215.4 |
| 2000 | 230.0 |
| 2001 | 235.0 |
| 2002 | 251.2 |
| 2003 | 276.4 |
| 2004 | 292.9 |
| 2005 | 310.7 |
| 2006 | 313.7 |
| 2007 | 314.9 |
| 2008 | 313.9 |
| 2009 | 319.2 |
| 2010 | 323.5 |
| 2011 | 318.0 |
| 2012 | 316.9 |
| 2013 | 313.2 |
| 2014 | 326.3 |
| 2015 | 340.5 |
| 2016 | 352.2 |
| 2017 | 358.3 |
| 2018 | 363.2 |
| 2019 | 367.6 |
| 2020 | 370.3 |
| 2021 | 371.2 |
| 2022 | 395.2 |
| 2023 | 409.2 |
| 2024 | 413.2 |