condition mean min max ZT0-3 21.9632 21.9632 21.9632 ZT4-7 8.50243 8.50243 8.50243 ZT8-11 12.42025 12.42025 12.42025 ZT12-15 26.5767 26.5767 26.5767 ZT16-19 45.8601 45.8601 45.8601 ZT20-23 39.9462 39.9462 39.9462