What is the kr td when mfg lg is 64?
CREATE TABLE "returning" (
  "player" text,
  "gp" real,
  "k_ret" real,
  "kr_yds" real,
  "kr_avg" text,
  "kr_td" real,
  "kr_lg" real,
  "p_ret" real,
  "pr_yds" real,
  "pr_avg" text,
  "pr_td" real,
  "pr_lg" real,
  "mfg_ret" real,
  "mfg_yds" real,
  "mfg_avg" text,
  "mfg_lg" real,
  "mfg_td" real
);
SELECT "kr_td" FROM "returning" WHERE "mfg_lg"=64;