condition mean min max ZT0-3 12.42185 12.42185 12.42185 ZT4-7 9.23132 9.23132 9.23132 ZT8-11 8.92465 8.92465 8.92465 ZT12-15 10.90775 10.90775 10.90775 ZT16-19 13.15265 13.15265 13.15265 ZT20-23 13.561900000000001 13.561900000000001 13.561900000000001