| Annual average | Management Contract Standard | |
|---|---|---|
| 2007 | 94.3 | 95 |
| 2008 | 95.8 | 95 |
| 2009 | 94.9 | 95 |
| 2010 | 95.3 | 95 |
| 2011 | 93.5 | 95 |
| 2012 | 95.3 | 95 |
| 2013 | 96.9 | 95 |
| 2014 | 96.1 | 95 |
| 2015 | 93.9 | 95 |
| 2016 | 93.3 | 95 |
| 2017 | 91.8 | 95 |
| 2018 | 87.3 | 95 |
| 2019 | 91.5 | 95 |
| 2020 | 88.2 | 95 |
| 2021 | 92.2 | 95 |
| 2022 | 93.2 | 95 |