condition mean min max ZT0-3 7.851406 7.851406 7.851406 ZT4-7 11.350076 11.350076 11.350076 ZT8-11 12.7992055 12.7992055 12.7992055 ZT12-15 11.8023205 11.8023205 11.8023205 ZT16-19 12.722466 12.722466 12.722466 ZT20-23 11.459665000000001 11.459665000000001 11.459665000000001