A few maps to enhance your understanding of the geographical spread of parties and religions.
Example of relative votes:
"Hervormd" and "gereformeerd" are two flavours of Dutch Reformed, the one rather liberal, the other rather strict. We'll get back to the exact differences later. I use the Dutch words because both terms translate as "Reformed".
The province names and the amount of seats they would have if they were parties.
Province names Seats per province
The relative number of votes for a party in the twelve provinces, compared to the national average.
CDA PvdA SP VVD PVV GL CU D66 SGP
Religions as indicated in the 1971 census (the last held). Back then Islam was not yet a factor, and Flevoland was not yet a province.