condition mean min max ZT0-3 61.106785835 45.07387805 77.13969362 ZT4-7 39.630866145 31.505807465 47.755924825 ZT8-11 67.5299150625 59.066306645 75.99352348 ZT12-15 63.986198282500006 48.225864810000004 79.746531755 ZT16-19 32.427304695000004 28.370558115 36.484051275 ZT20-23 17.827302862499998 17.156775085 18.49783064