condition mean min max ZT0-3 3.1279583333333334 2.64238 3.56348 ZT4-7 3.263395 3.263395 3.263395 ZT8-11 5.333505000000001 5.333505000000001 5.333505000000001 ZT12-15 10.9458825 10.39413 11.497635 ZT16-19 10.267900000000001 10.267900000000001 10.267900000000001 ZT20-23 9.270575000000001 9.270575000000001 9.270575000000001