condition mean min max ZT0-3 13.061375 12.8614 13.26135 ZT4-7 8.280775 8.280775 8.280775 ZT8-11 8.12787 8.12787 8.12787 ZT12-15 0 0 0 ZT16-19 5.09701 5.09701 5.09701 ZT20-23 8.773060000000001 8.773060000000001 8.773060000000001