condition mean min max ZT0-3 6.659975 6.659975 6.659975 ZT4-7 6.7085550000000005 6.7085550000000005 6.7085550000000005 ZT8-11 5.4866150000000005 5.4866150000000005 5.4866150000000005 ZT12-15 4.727595 4.727595 4.727595 ZT16-19 6.224485 6.224485 6.224485 ZT20-23 5.65122 5.65122 5.65122