condition mean min max ZT0-3 261.898458 261.898458 261.898458 ZT4-7 215.266599 215.266599 215.266599 ZT8-11 166.6921475 166.6921475 166.6921475 ZT12-15 232.2463735 232.2463735 232.2463735 ZT16-19 339.078283 339.078283 339.078283 ZT20-23 506.939768 506.939768 506.939768