condition mean min max ZT0-3 3.4597433333333334 2.95601 4.000225 ZT4-7 1.259655 1.259655 1.259655 ZT8-11 1.3070249999999999 1.3070249999999999 1.3070249999999999 ZT12-15 4.5126225 2.6468 6.378445 ZT16-19 5.46227 5.46227 5.46227 ZT20-23 6.13125 6.13125 6.13125