condition mean min max ZT0-3 2.5863916666666666 0.57842 4.512755 ZT4-7 1.3897985 1.3897985 1.3897985 ZT8-11 0.8847555 0.8847555 0.8847555 ZT12-15 1.8120125 1.7171825 1.9068425 ZT16-19 2.709605 2.709605 2.709605 ZT20-23 5.83652 5.83652 5.83652