condition mean min max ZT0-3 8.15338 6.971675 9.335085 ZT4-7 6.80165 6.80165 6.80165 ZT8-11 4.033379999999999 4.033379999999999 4.033379999999999 ZT12-15 0 0 0 ZT16-19 9.92602 9.92602 9.92602 ZT20-23 7.723145 7.723145 7.723145