condition mean min max ZT0-3 6.18956 6.18956 6.18956 ZT4-7 5.330415 5.330415 5.330415 ZT8-11 5.60848 5.60848 5.60848 ZT12-15 5.071315 5.071315 5.071315 ZT16-19 7.7729099999999995 7.7729099999999995 7.7729099999999995 ZT20-23 6.45603 6.45603 6.45603