Database: european_football_2
Question: When was the first time did Kevin Constant have his highest crossing score? Give the date.
SQL: SELECT `date` FROM ( SELECT t2.crossing, t2.`date` FROM Player AS t1 INNER JOIN Player_Attributes AS t2 ON t1.player_fifa_api_id = t2.player_fifa_api_id WHERE t1.player_name = 'Kevin Constant' ORDER BY t2.crossing DESC) ORDER BY date DESC LIMIT 1