condition mean min max ZT0-3 2.22348085825 0.8753122059999999 3.5716495105 ZT4-7 7.246709710499999 6.828350673 7.6650687479999995 ZT8-11 8.29265924825 7.542770185 9.0425483115 ZT12-15 18.326259715 17.319192905 19.333326525 ZT16-19 23.2677030875 22.582721194999998 23.95268498 ZT20-23 26.977853155 26.349787035 27.605919274999998