condition mean min max ZT0-3 12.3933 12.3933 12.3933 ZT4-7 10.276135 10.276135 10.276135 ZT8-11 8.213775 8.213775 8.213775 ZT12-15 9.01333 9.01333 9.01333 ZT16-19 11.6186 11.6186 11.6186 ZT20-23 11.5137 11.5137 11.5137