condition mean min max ZT0-3 5.937086666666667 5.209009999999999 6.590465 ZT4-7 4.3724050000000005 4.3724050000000005 4.3724050000000005 ZT8-11 5.505235 5.505235 5.505235 ZT12-15 8.62369 8.017855 9.229525 ZT16-19 6.5032049999999995 6.5032049999999995 6.5032049999999995 ZT20-23 5.88073 5.88073 5.88073