condition mean min max ZT0-3 21.92145 19.7334 24.109499999999997 ZT4-7 25.6241 25.6241 25.6241 ZT8-11 30.712600000000002 30.712600000000002 30.712600000000002 ZT12-15 0 0 0 ZT16-19 29.241300000000003 29.241300000000003 29.241300000000003 ZT20-23 27.49205 27.49205 27.49205