Name the lead margin for democrat john lynch being 62%
CREATE TABLE "opinion_polling_for_the_united_states_gu" (
  "poll_source" text,
  "dates_administered" text,
  "democrat_john_lynch" text,
  "republican_joe_kenney" text,
  "lead_margin" real
);
SELECT "lead_margin" FROM "opinion_polling_for_the_united_states_gu" WHERE "democrat_john_lynch"='62%';