Meanings of slipped somewhat in English

Eamonn McCann's Socialist Environmental Alliance polled impressively here in 2003, but has slipped somewhat in the meantime.

Oil has slipped somewhat after Russia and de facto OPEC leader Saudi Arabia discussed partly restoring output halted under the 2017 accord.

However, the issue has slipped somewhat from the top of the agenda since the new year began, overshadowed by military operations in Helmand.

Readers of the Melbourne Age and Sydney Morning Herald might be forgiven today for wondering if the standard of their newspapers has slipped somewhat.