condition mean min max ZT0-3 1.760485 1.760485 1.760485 ZT4-7 1.8904999999999998 1.8904999999999998 1.8904999999999998 ZT8-11 4.096959999999999 4.096959999999999 4.096959999999999 ZT12-15 3.34775 3.34775 3.34775 ZT16-19 5.1943850000000005 5.1943850000000005 5.1943850000000005 ZT20-23 1.6716099999999998 1.6716099999999998 1.6716099999999998