condition mean min max ZT0-3 7.495478333333334 3.93712 9.300665 ZT4-7 4.471285 4.471285 4.471285 ZT8-11 3.3982900000000003 3.3982900000000003 3.3982900000000003 ZT12-15 4.667525 4.497225 4.8378250000000005 ZT16-19 6.086684999999999 6.086684999999999 6.086684999999999 ZT20-23 9.476925000000001 9.476925000000001 9.476925000000001