I've added the acting WHC members as additional information to the Country- and Year-pages (except for Yugoslavia, still juggling how to technically handle a country that has split up in many pieces).
To see certain trends (I noticed that the USA has been a Member during no less than 20 of the 32 years!), I think I have to start a separate page including other trends like:
- countries with the most whs
- ...First Trends