condition mean min max ZT0-3 215.069522 215.069522 215.069522 ZT4-7 154.9747615 154.9747615 154.9747615 ZT8-11 173.30831 173.30831 173.30831 ZT12-15 235.099382 235.099382 235.099382 ZT16-19 322.985454 322.985454 322.985454 ZT20-23 299.483865 299.483865 299.483865