condition mean min max ZT0-3 2.082385 1.6025399999999999 2.56223 ZT4-7 4.730135 4.730135 4.730135 ZT8-11 7.4525950000000005 7.4525950000000005 7.4525950000000005 ZT12-15 0 0 0 ZT16-19 8.524495 8.524495 8.524495 ZT20-23 6.504144999999999 6.504144999999999 6.504144999999999