condition mean min max ZT0-3 13.719473 13.719473 13.719473 ZT4-7 13.8203635 13.8203635 13.8203635 ZT8-11 14.6803695 14.6803695 14.6803695 ZT12-15 17.356368000000003 17.356368000000003 17.356368000000003 ZT16-19 11.6951605 11.6951605 11.6951605 ZT20-23 13.855758 13.855758 13.855758