condition mean min max ZT0-3 5.551173333333334 5.551173333333334 5.551173333333334 ZT4-7 3.839045 3.839045 3.839045 ZT8-11 1.9524599999999999 1.9524599999999999 1.9524599999999999 ZT12-15 3.0618800000000004 3.0618800000000004 3.0618800000000004 ZT16-19 5.06816 5.06816 5.06816 ZT20-23 9.09802 9.09802 9.09802