condition mean min max ZT0-3 0.92902102 0.0 1.85804204 ZT4-7 6.6337870115 4.610322346 8.657251677 ZT8-11 14.02844003725 12.549964875 15.5069151995 ZT12-15 38.16269493 29.020962660000002 47.304427200000006 ZT16-19 34.5381280775 27.90428217 41.171973985 ZT20-23 12.8900206715 11.131257102 14.648784241000001