condition mean min max ZT0-3 20.794333333333334 18.2571 24.5685 ZT4-7 20.01285 20.01285 20.01285 ZT8-11 15.124500000000001 15.124500000000001 15.124500000000001 ZT12-15 14.276499999999999 13.2752 15.2778 ZT16-19 14.38465 14.38465 14.38465 ZT20-23 16.3792 16.3792 16.3792