condition mean min max ZT0-3 8.391425 8.391425 8.391425 ZT4-7 12.61715 12.61715 12.61715 ZT8-11 6.18987 6.18987 6.18987 ZT12-15 3.85851 3.85851 3.85851 ZT16-19 6.164605 6.164605 6.164605 ZT20-23 6.85 6.85 6.85