condition mean min max ZT0-3 16.23265 15.883049999999999 16.582250000000002 ZT4-7 8.774525 8.774525 8.774525 ZT8-11 7.81429 7.81429 7.81429 ZT12-15 0 0 0 ZT16-19 21.718600000000002 21.718600000000002 21.718600000000002 ZT20-23 20.6896 20.6896 20.6896