condition mean min max ZT0-3 6.9911025 6.3750350000000005 7.60717 ZT4-7 16.9712 16.9712 16.9712 ZT8-11 13.187005 13.187005 13.187005 ZT12-15 0 0 0 ZT16-19 17.446550000000002 17.446550000000002 17.446550000000002 ZT20-23 13.456 13.456 13.456