condition mean min max ZT0-3 2.992925 2.992925 2.992925 ZT4-7 1.2365499999999998 1.2365499999999998 1.2365499999999998 ZT8-11 1.66157 1.66157 1.66157 ZT12-15 3.0578000000000003 3.0578000000000003 3.0578000000000003 ZT16-19 4.26554 4.26554 4.26554 ZT20-23 3.676825 3.676825 3.676825