condition mean min max ZT0-3 3.696235 3.53234 3.8601300000000003 ZT4-7 4.215015 4.215015 4.215015 ZT8-11 10.9314 10.9314 10.9314 ZT12-15 0 0 0 ZT16-19 9.155775 9.155775 9.155775 ZT20-23 6.49417 6.49417 6.49417