The document really doesn't provide sources- and that is frustrating.
One can make an assumption that the data was collected from the Oregon Vital Statistics office. We're left to make some assumptions about the .6/1000 hospital rate - because that must exclude many higher risk births.
This document states that OR on a whole has a lower average neonatal mortality rate than the rest of the US. But this number is reported to be 3.8/1000.
More detail would be helpful in understanding how those numbers were generated. I agree.