condition mean min max ZT0-3 5.600763333333333 5.600763333333333 5.600763333333333 ZT4-7 3.825515 3.825515 3.825515 ZT8-11 2.5444250000000004 2.5444250000000004 2.5444250000000004 ZT12-15 3.0739099999999997 3.0739099999999997 3.0739099999999997 ZT16-19 5.53404 5.53404 5.53404 ZT20-23 5.59435 5.59435 5.59435