condition mean min max ZT0-3 0.836557 0.836557 0.836557 ZT4-7 0.2910595 0.2910595 0.2910595 ZT8-11 0.342863 0.342863 0.342863 ZT12-15 0.289501 0.289501 0.289501 ZT16-19 1.359295 1.359295 1.359295 ZT20-23 0.714836 0.714836 0.714836