condition mean min max ZT0-3 2.2120575000000002 1.983035 2.44108 ZT4-7 2.0060000000000002 2.0060000000000002 2.0060000000000002 ZT8-11 0.7387205 0.7387205 0.7387205 ZT12-15 0 0 0 ZT16-19 2.276665 2.276665 2.276665 ZT20-23 1.9519099999999998 1.9519099999999998 1.9519099999999998