Stats came from Ark and were slightly out for SF in 2007, it doesn’t affect the trends but corrected version can be seen here.
It can be difficult to spot all the trends that may occur in our election results with random factors of personalities in Europe, come and go minor Unionist parties, independents and small parties. I have tried to simplify matters a little by taking results from 1996 on, removing European results, smaller parties and Independents to produce the above graph of party percentage of the vote for the top five over the last 15 years. Of course it is going to miss some major factors in play but you can’t have everything with simplicity.
Adds: Was requested to add other parties (all those getting over 1% on the below graph)
Adds Further: made a small error, so graphs above updated. Also adding graphs to include Euros below (I added Gilliland’s vote as Alliance in Euros) – starts to get confused but done for completeness. *
*Graphs with Euro results confused matters so were removed – should be part of a further entry on this.
A quick translation of the graphs to sectarian basics: