condition mean min max ZT0-3 2.618438333333333 2.3581250000000002 2.923685 ZT4-7 1.5339450000000001 1.5339450000000001 1.5339450000000001 ZT8-11 2.770295 2.770295 2.770295 ZT12-15 4.2118325 3.8476399999999997 4.576025 ZT16-19 4.86366 4.86366 4.86366 ZT20-23 5.33554 5.33554 5.33554