condition mean min max ZT0-3 12.737371 12.737371 12.737371 ZT4-7 12.7893565 12.7893565 12.7893565 ZT8-11 14.670318000000002 14.670318000000002 14.670318000000002 ZT12-15 14.178035999999999 14.178035999999999 14.178035999999999 ZT16-19 13.978014 13.978014 13.978014 ZT20-23 16.998196 16.998196 16.998196