condition mean min max ZT0-3 6664.321377 6664.321377 6664.321377 ZT4-7 5366.277224 5366.277224 5366.277224 ZT8-11 5306.939399 5306.939399 5306.939399 ZT12-15 5600.587932 5600.587932 5600.587932 ZT16-19 6535.237317499999 6535.237317499999 6535.237317499999 ZT20-23 6754.2949835 6754.2949835 6754.2949835