What Evidence can be said of a 3 Party [or Multi-Party] System in the UK? (EX)

-2019 saw 82 MPs Elected from Outside the 2 Main Parties, which is Huge Increase from 9 during the 1950-70s -Green Party has Caroline Lucas Represent the Brighton Pavilion, and has Increased her Majority over the last GEs -2019 GE saw the SNP get 48 Seats in HoC, meaning it became the 3rd Largest Comfortably