condition mean min max ZT0-3 15.604133333333332 13.504349999999999 17.4472 ZT4-7 15.237449999999999 15.237449999999999 15.237449999999999 ZT8-11 20.0782 20.0782 20.0782 ZT12-15 22.073875 21.2793 22.868450000000003 ZT16-19 15.81355 15.81355 15.81355 ZT20-23 19.4212 19.4212 19.4212