condition mean min max ZT0-3 27.612225000000002 23.77985 31.4446 ZT4-7 27.4437 27.4437 27.4437 ZT8-11 26.23525 26.23525 26.23525 ZT12-15 0 0 0 ZT16-19 26.010350000000003 26.010350000000003 26.010350000000003 ZT20-23 28.0305 28.0305 28.0305