question_text: How many years before William Y. Giles presented the league champion Astros with the Warren C. Giles Trophy did Williams father, Warren Giles, award an MLB franchise to the city of Houston?
decomposition: return year when  William Y. Giles presented the  league champion Astros with the   Warren  C. Giles  Trophy ;return year when  Warren Giles awarded an MLB franchise to the  city of Houston ;return the  difference of #2 and  #1