condition mean min max ZT0-3 13.95 13.95 13.95 ZT4-7 33.0 33.0 33.0 ZT8-11 22.450000000000003 22.450000000000003 22.450000000000003 ZT12-15 39.6 39.6 39.6 ZT16-19 7.5 7.5 7.5 ZT20-23 8.75 8.75 8.75