condition mean min max ZT0-3 16.482325 16.26965 16.695 ZT4-7 14.7409 14.7409 14.7409 ZT8-11 16.62325 16.62325 16.62325 ZT12-15 0 0 0 ZT16-19 20.6597 20.6597 20.6597 ZT20-23 19.990650000000002 19.990650000000002 19.990650000000002