Question: Which Hereditary peers have a Total of 1?
SQL: SELECT "Hereditary peers" FROM "2-13658-1" WHERE "Total" = 1.0;

Question: Which Total has a Hereditary peer of –, and a Lords spiritual of –, and a Life peers of 2, and an Affiliation of plaid cymru?
SQL: SELECT COUNT("Total") FROM "2-13658-1" WHERE "Hereditary peers" = '–' AND "Lords spiritual" = '–' AND "Life peers" = '2' AND "Affiliation" = 'plaid cymru';