condition mean min max ZT0-3 22.775628 22.775628 22.775628 ZT4-7 17.2985255 17.2985255 17.2985255 ZT8-11 9.8143875 9.8143875 9.8143875 ZT12-15 11.3416865 11.3416865 11.3416865 ZT16-19 8.5465135 8.5465135 8.5465135 ZT20-23 9.771359 9.771359 9.771359