condition mean min max ZT0-3 17.7984 17.7984 17.7984 ZT4-7 13.454 13.454 13.454 ZT8-11 12.4872 12.4872 12.4872 ZT12-15 16.1899 16.1899 16.1899 ZT16-19 17.333750000000002 17.333750000000002 17.333750000000002 ZT20-23 18.18075 18.18075 18.18075