condition mean min max ZT0-3 13.590016666666667 12.6689 15.3125 ZT4-7 11.28295 11.28295 11.28295 ZT8-11 10.857700000000001 10.857700000000001 10.857700000000001 ZT12-15 20.82365 20.643900000000002 21.0034 ZT16-19 15.1862 15.1862 15.1862 ZT20-23 15.2989 15.2989 15.2989