condition mean min max ZT0-3 229.424258 229.424258 229.424258 ZT4-7 254.54599050000002 254.54599050000002 254.54599050000002 ZT8-11 275.0239695 275.0239695 275.0239695 ZT12-15 311.6795885 311.6795885 311.6795885 ZT16-19 305.20734849999997 305.20734849999997 305.20734849999997 ZT20-23 291.997443 291.997443 291.997443