During the period in which gross sales totals for "The Show Girl Must Go On" reached $2,628,457, what did the numbers show for tickets sold/ available at the box office? 
CREATE TABLE "table1_22123920_4" (
  "dates_mdy" text,
  "gross_sales" text,
  "tickets_sold_available" text,
  "shows_sellout" text,
  "sellout_pct" text
);
SELECT "tickets_sold_available" FROM "table1_22123920_4" WHERE "gross_sales"='$2,628,457';