condition mean min max ZT0-3 18.06705 18.06705 18.06705 ZT4-7 19.047175 19.047175 19.047175 ZT8-11 30.4552 30.4552 30.4552 ZT12-15 30.531875 30.531875 30.531875 ZT16-19 24.0604 24.0604 24.0604 ZT20-23 22.054608333333334 22.054608333333334 22.054608333333334