condition mean min max ZT0-3 2.1682699999999997 2.164005 2.172535 ZT4-7 3.763945 3.763945 3.763945 ZT8-11 7.188245 7.188245 7.188245 ZT12-15 0 0 0 ZT16-19 4.30747 4.30747 4.30747 ZT20-23 4.251005 4.251005 4.251005