condition mean min max ZT0-3 14.99955 14.0511 15.948 ZT4-7 21.5729 21.5729 21.5729 ZT8-11 21.9506 21.9506 21.9506 ZT12-15 0 0 0 ZT16-19 22.7346 22.7346 22.7346 ZT20-23 17.8767 17.8767 17.8767