With the adoption of the Nature Restoration Law last summer the Grassland Butterfly Index (GBI) is one of the indicators for biodiversity in agricultural ecosystems (art. 11). The GBI for both EU27 and NL show a marked decline after 2012 with no sign of slowing down.
https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=OJ:L_202401991