condition mean min max ZT0-3 18.494275000000002 17.60905 19.3795 ZT4-7 17.1477 17.1477 17.1477 ZT8-11 19.259050000000002 19.259050000000002 19.259050000000002 ZT12-15 0 0 0 ZT16-19 22.57095 22.57095 22.57095 ZT20-23 21.99355 21.99355 21.99355