condition mean min max ZT0-3 1.8583668064999999 0.9745539520000001 2.7421796609999998 ZT4-7 3.381798544 2.7386555495 4.0249415385 ZT8-11 4.651000325 2.7687551074999996 6.5332455425 ZT12-15 6.86929759325 5.586418767 8.1521764195 ZT16-19 7.6876134915 7.344774055 8.030452927999999 ZT20-23 6.8479488495 6.3300074825 7.365890216499999