condition mean min max ZT0-3 15.762014 15.762014 15.762014 ZT4-7 14.7633375 14.7633375 14.7633375 ZT8-11 15.0796035 15.0796035 15.0796035 ZT12-15 15.058237 15.058237 15.058237 ZT16-19 14.582385500000001 14.582385500000001 14.582385500000001 ZT20-23 15.328162 15.328162 15.328162