| 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | |
| January | 17 | 11 | 6 | 13 | 10 | 12 | 16 |
| February | 13 | 14 | 13 | 21 | 14 | 15 | 22 |
| March | 19 | 10 | 14 | 28 | 21 | 19 | 22 |
| April | 9 | 12 | 16 | 17 | 18 | 18 | 26 |
| May | 20 | 10 | 17 | 20 | 12 | 23 | 13 |
| June | 28 | 20 | 15 | 10 | 16 | 23 | 19 |
| July | 21 | 25 | 30 | 16 | 25 | 30 | |
| August | 15 | 12 | 32 | 19 | 20 | 24 | |
| September | 14 | 14 | 7 | 18 | 17 | 33 | |
| October | 12 | 22 | 6 | 15 | 20 | 31 | |
| November | 20 | 17 | 15 | 12 | 19 | 19 | |
| December | 10 | 15 | 19 | 12 | 19 | 20 | |
| Total | 106 | 169 | 186 | 218 | 183 | 230 | 275 |
