In group I , the mean % EWL was 51.813.9 , 63.816.1 and 71.812 ; however , in group II , the mean % EWL was 38.310.9 , 51.913.6 and 6111.1 at 6 , 12 , and 24 months , respectively ( P = 0.0001 , 0.0001 , 0.003 ) .