condition mean min max ZT0-3 3.2991318333333335 2.4108155 4.19324 ZT4-7 2.8639 2.8639 2.8639 ZT8-11 2.56703 2.56703 2.56703 ZT12-15 8.0441375 7.040685 9.04759 ZT16-19 5.027005 5.027005 5.027005 ZT20-23 5.49658 5.49658 5.49658