condition mean min max ZT0-3 218.683366 218.683366 218.683366 ZT4-7 156.484392 156.484392 156.484392 ZT8-11 150.139364 150.139364 150.139364 ZT12-15 191.3419925 191.3419925 191.3419925 ZT16-19 196.5470475 196.5470475 196.5470475 ZT20-23 252.96718149999998 252.96718149999998 252.96718149999998