condition mean min max ZT0-3 11.203113333333333 8.20429 13.4262 ZT4-7 9.631810000000002 9.631810000000002 9.631810000000002 ZT8-11 8.832925 8.832925 8.832925 ZT12-15 9.288455 9.042355 9.534555000000001 ZT16-19 11.585799999999999 11.585799999999999 11.585799999999999 ZT20-23 14.0839 14.0839 14.0839