For a good part of that time the interest was actually quite a bit higher than 4%, so it wouldn't surprise me if the calculation with actual interest rates is a

For a good part of that time the interest was actually quite a bit higher than 4%, so it wouldn't surprise me if the calculation with actual interest rates is absolutely spot on. Swedish government tends to be like that more often than not: Unreasonable, but rarely completely wrong in a way you actually can point out - or prove - for that matter.