condition mean min max ZT0-3 3.287845 2.92868 3.64701 ZT4-7 2.38206 2.38206 2.38206 ZT8-11 3.953685 3.953685 3.953685 ZT12-15 0 0 0 ZT16-19 4.27442 4.27442 4.27442 ZT20-23 3.2464500000000003 3.2464500000000003 3.2464500000000003