What are the gains for the player with average of 26.8 and lost yard fewer than 13?
CREATE TABLE "rushing_sortable_options" (
  "name" text,
  "gain" real,
  "loss" real,
  "long" real,
  "avg_g" text
);
SELECT SUM("gain") FROM "rushing_sortable_options" WHERE "avg_g"='26.8' AND "loss"<13;