condition mean min max ZT0-3 14.574918333333333 5.0340050000000005 20.865099999999998 ZT4-7 4.021205 4.021205 4.021205 ZT8-11 5.96258 5.96258 5.96258 ZT12-15 10.9284975 8.965795 12.891200000000001 ZT16-19 18.3298 18.3298 18.3298 ZT20-23 25.448050000000002 25.448050000000002 25.448050000000002