condition mean min max ZT0-3 9.715489999999999 9.715489999999999 9.715489999999999 ZT4-7 7.23287 7.23287 7.23287 ZT8-11 6.8898600000000005 6.8898600000000005 6.8898600000000005 ZT12-15 9.39103 9.39103 9.39103 ZT16-19 11.104600000000001 11.104600000000001 11.104600000000001 ZT20-23 10.88965 10.88965 10.88965