Thank you for this solution, but my goal is not to use R for the statistics. I will be using Python for all my statistics and graphs. The error with the missing values is not a dealbraker as I can recode the values in Python. But I would rather not have to.
Kind Regards Henning Langen Stokmo
Twitter: @helangen Keybase: @helangen PGP fingerprint: 9C50 5F2D BDB7 F13A