condition mean min max ZT0-3 31.041417275 29.27681309 32.80602146 ZT4-7 12.7552647275 10.069846505000001 15.44068295 ZT8-11 10.94261342175 9.458575832000001 12.426651011499999 ZT12-15 18.018443322499998 13.610139310000001 22.426747334999998 ZT16-19 25.835578052499997 24.872198224999998 26.79895788 ZT20-23 24.9348042825 23.638259050000002 26.231349514999998