condition mean min max ZT0-3 3.909823333333333 1.94654 6.75679 ZT4-7 1.393105 1.393105 1.393105 ZT8-11 0.9647295 0.9647295 0.9647295 ZT12-15 6.514715000000001 6.4101300000000005 6.6193 ZT16-19 4.228705 4.228705 4.228705 ZT20-23 3.83595 3.83595 3.83595