condition mean min max ZT0-3 3.9953499999999997 3.9953499999999997 3.9953499999999997 ZT4-7 2.89123 2.89123 2.89123 ZT8-11 5.127325 5.127325 5.127325 ZT12-15 7.56141 7.56141 7.56141 ZT16-19 6.40947 6.40947 6.40947 ZT20-23 3.22139 3.22139 3.22139