condition mean min max ZT0-3 7.143545 7.143545 7.143545 ZT4-7 4.020325 4.020325 4.020325 ZT8-11 3.347245 3.347245 3.347245 ZT12-15 4.81234 4.81234 4.81234 ZT16-19 8.717115 8.717115 8.717115 ZT20-23 9.398165 9.398165 9.398165