condition mean min max ZT0-3 2.04995417625 2.0443094525 2.0555988999999997 ZT4-7 2.00945254075 1.7050389605 2.313866121 ZT8-11 2.36489520075 2.0979520239999996 2.6318383775000003 ZT12-15 1.1098122975 0.8505923815 1.3690322135000002 ZT16-19 1.21935371975 0.984282179 1.4544252604999999 ZT20-23 1.82470396625 1.6842235755 1.965184357