Some put there prices up once a year and some others put them up every other year.
But as there is two budgets in a year now and shop puts there prices up every week without of anyone knowing it and it maybe pence to some but it works out for lot of pounds for them.
In respect a pound a year across the board meaning small to large accounts isn't to much of pay rise every year and clients wont disagree with that extra pound every year as they might have a pay rise more than that.
So the answer to your question is yes indeed put your prices up.
At the end of the day you deserve it for all the hard work that we all do.