condition mean min max ZT0-3 4.8546 4.8546 4.8546 ZT4-7 4.263545 4.263545 4.263545 ZT8-11 6.425265 6.425265 6.425265 ZT12-15 7.6487300000000005 7.6487300000000005 7.6487300000000005 ZT16-19 9.578524999999999 9.578524999999999 9.578524999999999 ZT20-23 4.79893 4.79893 4.79893