condition mean min max ZT0-3 3.219105 2.90776 3.53045 ZT4-7 1.72532 1.72532 1.72532 ZT8-11 1.716465 1.716465 1.716465 ZT12-15 0 0 0 ZT16-19 3.430705 3.430705 3.430705 ZT20-23 3.70526 3.70526 3.70526