condition mean min max ZT0-3 1.3081756666666666 1.1503755 1.55151 ZT4-7 2.93955 2.93955 2.93955 ZT8-11 16.5563 16.5563 16.5563 ZT12-15 6.7908025 3.952595 9.62901 ZT16-19 3.38957 3.38957 3.38957 ZT20-23 2.62455 2.62455 2.62455