condition mean min max ZT0-3 1.2916249999999998 1.2916249999999998 1.2916249999999998 ZT4-7 0.513218 0.513218 0.513218 ZT8-11 0.8013445 0.8013445 0.8013445 ZT12-15 1.094362 1.094362 1.094362 ZT16-19 1.167687 1.167687 1.167687 ZT20-23 1.09555 1.09555 1.09555