North Dakota test scores pretty much unchanged from two years ago. Worst news: North Dakota 8th graders scored below the national average in reading in 2017, and barely scored better in any comparison, although NAEP ranks ND "much higher" in most (all?) categories. Link here for this screenshot:
Full data here. Interactive. State-by-stage. Year of Survey. Grade level. Mathematics and reading. Easy to navigate. Make sure you are looking at correct year when going through the interactive page.