What else happened during that period that could explain the decline.

RT @MauritsGroen@twitter.com

Since The Netherlands adopted a small deposit on small plastic bottles the number of thrown-away bottles on the streets immediately dropped 70%. It took much civil action energy and many years to convince government to take this super simple measure…

🐦🔗: https://twitter.com/MauritsGroen/status/1479134765387235333