| Year | Quarter 1 | Quarter 2 | Quarter 3 | Quarter 4 |
|---|---|---|---|---|
| 2009 | XXX | 15 | 15 | 15 |
| 2010 | 15 | 15 | 15 | 15 |
| 2011 | 15 | 15 | 15 | 15 |
| 2012 | 15 | 15 | 16 | 16 |
| 2013 | 16 | 17 | 17 | 17 |
| 2014 | 17 | 19 | 19 | 19 |
| 2015 | 19 | 19 | 19 | 19 |
| 2016 | 19 | 19 | 19 | 19 |
| 2017 | 19 | 19 | 20 | 21 |
| 2018 | 21 | 21 | 21 | 21 |
| 2019 | 21 | 21 | 21 | 21 |
| 2020 | 21 | 21 | 21 | 21 |
| 2021 | 21 | 21 | 21 | 21 |
| 2022 | 21 | 21 | 21 | 21 |
| 2023 | 21 | 21 | 21 | 21 |
| 2024 | 21 | XXX | XXX | XXX |