condition mean min max ZT0-3 1316.586297 1316.586297 1316.586297 ZT4-7 972.8323235 972.8323235 972.8323235 ZT8-11 1064.691566 1064.691566 1064.691566 ZT12-15 1222.3602805 1222.3602805 1222.3602805 ZT16-19 1102.740038 1102.740038 1102.740038 ZT20-23 825.3312225 825.3312225 825.3312225