condition mean min max ZT0-3 0.374297 0.374297 0.374297 ZT4-7 0.3474935 0.3474935 0.3474935 ZT8-11 0.15080149999999998 0.15080149999999998 0.15080149999999998 ZT12-15 0.320625 0.320625 0.320625 ZT16-19 0.284277 0.284277 0.284277 ZT20-23 0.560956 0.560956 0.560956