condition mean min max ZT0-3 7.674643333333333 6.25038 8.63987 ZT4-7 9.158104999999999 9.158104999999999 9.158104999999999 ZT8-11 8.057690000000001 8.057690000000001 8.057690000000001 ZT12-15 7.8290725000000005 7.31553 8.342615 ZT16-19 9.38906 9.38906 9.38906 ZT20-23 7.275035 7.275035 7.275035