condition mean min max ZT0-3 13.389225 12.3416 14.43685 ZT4-7 6.18657 6.18657 6.18657 ZT8-11 8.438790000000001 8.438790000000001 8.438790000000001 ZT12-15 0 0 0 ZT16-19 11.806750000000001 11.806750000000001 11.806750000000001 ZT20-23 12.680299999999999 12.680299999999999 12.680299999999999