its fptp with contested third party & its not granular update i think, they’ll still remain in some seats. (but its good for the memes)

The Liberal Party of the UK went from 43,2% in 1910 (272 seats) to 13,0% in the next election of 1918 (36 seats).

The Panhellenic Socialist Movement (Socdems) in Greece had almost the same fall - 43,9% in 2009 to 13,8% in 2012. So much that the decline of socdem parties became known as PASOKification.

The Polish Democratic Left Alliance, the successor of the PZPR, got into power with 41,0% of the vote (compared to the second placed PO with 12,7%) in 2001, but a mixture of neoliberal reforms and scandals made them fall to 11,31% in 2005, which also led to the rise of the far-right.