condition mean min max ZT0-3 2.1562200000000002 2.1562200000000002 2.1562200000000002 ZT4-7 1.53941 1.53941 1.53941 ZT8-11 0.4726975 0.4726975 0.4726975 ZT12-15 0.7098255 0.7098255 0.7098255 ZT16-19 1.6102823333333334 1.6102823333333334 1.6102823333333334 ZT20-23 1.1741139999999999 1.1741139999999999 1.1741139999999999