condition mean min max ZT0-3 3.3040335 1.181602 5.426465 ZT4-7 23.366249999999997 23.366249999999997 23.366249999999997 ZT8-11 7.54116 7.54116 7.54116 ZT12-15 0 0 0 ZT16-19 9.18632 9.18632 9.18632 ZT20-23 51.93385 51.93385 51.93385