condition mean min max ZT0-3 12.11557 11.15339 13.07775 ZT4-7 7.181229999999999 7.181229999999999 7.181229999999999 ZT8-11 8.82713 8.82713 8.82713 ZT12-15 0 0 0 ZT16-19 15.45505 15.45505 15.45505 ZT20-23 11.30345 11.30345 11.30345