| Year | First Half | Second Half |
|---|---|---|
| 2015 | June | December |
| 2016 | June | December |
| 2017 | June | December |
| 2018 | June | December CBGS December CBCS |
| 2019 | June CBGS June CBCS | December CBGS December CBCS |
| 2020 | December CBGS December CBCS | |
| 2021 | June CBCS | December R 2019-C Scheme |
| 2022 | December ECS |
