condition mean min max ZT0-3 3.6168050000000003 3.50095 3.73266 ZT4-7 4.397455 4.397455 4.397455 ZT8-11 3.785745 3.785745 3.785745 ZT12-15 0 0 0 ZT16-19 4.589365 4.589365 4.589365 ZT20-23 6.478675 6.478675 6.478675