condition mean min max ZT0-3 7.064116666666667 5.53173 8.679085 ZT4-7 7.833275 7.833275 7.833275 ZT8-11 6.573105 6.573105 6.573105 ZT12-15 7.7465174999999995 7.556775 7.936259999999999 ZT16-19 10.359 10.359 10.359 ZT20-23 10.902149999999999 10.902149999999999 10.902149999999999