Table: six_nations_squads_2008_2
Columns: player
position
date_of_birth_age
caps
club_province

Question: When was the player with 51 caps from a Club/province of clermont born?
SQL: SELECT "date_of_birth_age" FROM six_nations_squads_2008_2 WHERE "caps" = 51 AND "club_province" = 'clermont'