condition mean min max ZT0-3 7.7995350000000006 7.7995350000000006 7.7995350000000006 ZT4-7 4.00558 4.00558 4.00558 ZT8-11 3.3157550000000002 3.3157550000000002 3.3157550000000002 ZT12-15 5.93247 5.93247 5.93247 ZT16-19 14.191980000000001 14.191980000000001 14.191980000000001 ZT20-23 8.380505 8.380505 8.380505