condition mean min max ZT0-3 8.058403333333334 6.427115000000001 10.306685000000002 ZT4-7 6.722754999999999 6.722754999999999 6.722754999999999 ZT8-11 8.265025 8.265025 8.265025 ZT12-15 13.091825 12.4301 13.75355 ZT16-19 13.7866 13.7866 13.7866 ZT20-23 15.875399999999999 15.875399999999999 15.875399999999999