condition mean min max ZT0-3 1.7661419999999999 1.7661419999999999 1.7661419999999999 ZT4-7 3.507834 3.507834 3.507834 ZT8-11 2.9831676666666667 2.9831676666666667 2.9831676666666667 ZT12-15 1.663988 1.663988 1.663988 ZT16-19 3.34615 3.34615 3.34615 ZT20-23 2.9142870000000003 2.9142870000000003 2.9142870000000003