condition mean min max ZT0-3 12.2315 12.2315 12.2315 ZT4-7 5.193885 5.193885 5.193885 ZT8-11 3.6033049999999998 3.6033049999999998 3.6033049999999998 ZT12-15 5.43356 5.43356 5.43356 ZT16-19 7.67256 7.67256 7.67256 ZT20-23 13.8781 13.8781 13.8781