condition mean min max ZT0-3 16.13004 10.035070000000001 19.829549999999998 ZT4-7 7.926355000000001 7.926355000000001 7.926355000000001 ZT8-11 7.56858 7.56858 7.56858 ZT12-15 11.794125000000001 11.562100000000001 12.026150000000001 ZT16-19 15.3828 15.3828 15.3828 ZT20-23 21.8829 21.8829 21.8829