condition mean min max ZT0-3 9.563814230750001 7.691600531500001 11.43602793 ZT4-7 3.03638736625 2.4724154865 3.600359246 ZT8-11 8.10511799575 6.577942569 9.6322934225 ZT12-15 6.829726869 5.997577894 7.661875844 ZT16-19 3.6937127915 3.2086743735 4.1787512095 ZT20-23 4.962800368250001 4.778255871000001 5.1473448655