condition mean min max ZT0-3 2.09194 2.09194 2.09194 ZT4-7 1.5033699999999999 1.5033699999999999 1.5033699999999999 ZT8-11 3.079035 3.079035 3.079035 ZT12-15 3.0712900000000003 3.0712900000000003 3.0712900000000003 ZT16-19 3.11937 3.11937 3.11937 ZT20-23 2.469335 2.469335 2.469335