As of 2020, the EU-AITF has switched to an annual reporting frequency.
You can access the:
2015 S2 monitoring report here (restricted access).
2016 S1 monitoring report here (restricted access).
2016 S2 monitoring report here (restricted access).
2017 S1 monitoring report here (restricted access).
2017 S2 monitoring report here (restricted access).
2018 S1 monitoring report here (restricted access).
2018 S2 monitoring report here (restricted access).
2019 S1 monitoring report here (restricted access).
2019 S2 monitoring report here (restricted access).
2020 monitoring report here (restricted access).
2021 monitoring report here (restricted access).
2022 monitoring report here (restricted access).
2023 monitoring report here (restricted access).