condition mean min max ZT0-3 8.303915 8.043935000000001 8.563895 ZT4-7 7.391540000000001 7.391540000000001 7.391540000000001 ZT8-11 5.63176 5.63176 5.63176 ZT12-15 0 0 0 ZT16-19 4.369675 4.369675 4.369675 ZT20-23 6.338 6.338 6.338