condition mean min max ZT0-3 18.556425 17.2382 19.874650000000003 ZT4-7 16.88655 16.88655 16.88655 ZT8-11 13.7072 13.7072 13.7072 ZT12-15 0 0 0 ZT16-19 21.0531 21.0531 21.0531 ZT20-23 19.634149999999998 19.634149999999998 19.634149999999998