condition mean min max ZT0-3 7.527535 7.356355000000001 7.764424999999999 ZT4-7 4.77341 4.77341 4.77341 ZT8-11 2.469395 2.469395 2.469395 ZT12-15 1.3647175 0.0 2.729435 ZT16-19 4.77021 4.77021 4.77021 ZT20-23 10.75785 10.75785 10.75785