condition mean min max ZT0-3 1.719865 1.52013 1.9196 ZT4-7 1.8995199999999999 1.8995199999999999 1.8995199999999999 ZT8-11 1.65186 1.65186 1.65186 ZT12-15 0 0 0 ZT16-19 1.494505 1.494505 1.494505 ZT20-23 1.7956750000000001 1.7956750000000001 1.7956750000000001