condition mean min max ZT0-3 19.735275 19.51365 19.9569 ZT4-7 29.3155 29.3155 29.3155 ZT8-11 23.822200000000002 23.822200000000002 23.822200000000002 ZT12-15 0 0 0 ZT16-19 25.38205 25.38205 25.38205 ZT20-23 25.11975 25.11975 25.11975