They must be horribly swamped in Durham.
Millions of applicants now, and it's not hard to see why.
There are 29 countries to use the EU's free movement in but at the last count, 25% of EEA citizens who used the EU's free movement, came to the UK. Although Liechtenstein is allowed to restrict immigration to their country to just 66 EU permits a year. That was 3 million EEA citizens in the UK at the last count.
Then there all the millions of 3rd country nationals (non-EEA citizens) who have used EEA laws and European Court of Justice rulings to enter the UK. The UK list the numbers of immigrants under their nationality, so these don't feature in the UK stats of EU immigration, even though these are only in the UK as they are using EEA Regulations and court rulings. ? millions.
Then add in all those who have not been living lawfully in the UK (and the EU makes this very easy for them and hard for an EEA country to find and deport them). Brexit has focused their minds to start being lawfully in the UK and some of these are applying for RCs as proof they are in the UK (although these can become invalid and they are then no longer lawfully in the UK).
Then add in the predicted rush to the UK since the Leave decision, before the UK closes its immigration doors.
You can see why these queues for the various EU's Cards, will get longer.
We still have the registration before Brexit, for all those who can't have British citizenship before Brexit and who will be hoping to be allowed to stay when EU laws end. Considering all the millions in the UK using these various EU laws over the last few decades and that only half a million have managed to be granted British citizenship since the UK voted to leave the UK 14 months ago, this queue is likely to be long.
Expect lots of waiting.