what is the surface of the final which had score 6-2, 6-3
CREATE TABLE "mixed_doubles_7_5_titles_2_runner_ups" (
  "outcome" text,
  "year" real,
  "championship" text,
  "surface" text,
  "partner" text,
  "opponents_in_the_final" text,
  "score_in_the_final" text
);
SELECT "surface" FROM "mixed_doubles_7_5_titles_2_runner_ups" WHERE "score_in_the_final"='6-2, 6-3';