The Swedish Crime Writers Academy was founded in 1971 - awarding their prize to the best mystery translated into Swedish. Most important thing to note here - it doesn't have to be English translated into Swedish- it can be any other language French, Dutch, German and Norwegian language books have all had winners in this category. The very 1st winner was an English Language book by Julia Symons's called The 31st of February. Other examples of English language translation winners over the years: The Day of the Jackal, Berlin Game, LaBrava, A Perfect Spy, A Chinaman's Chance, Snow Falling on Cedars and Galveston.
From 1996 to 2008 the award was called the Martin Beck Award (I think that either they started the award or were founding members of the Academy - google translate was a little sketchy on this point)- after Sjowall & Wahloo's Stockholm detective and since 2009 on they switched the award to The Golden Crowbar (I think, once again the google translate was unclear and my Swedish lacking)!
Ten years later in 1981 they decided to to give out a new award to the Best (original) Swedish Crime Novel. Henning Mankell, Hakan Nesser, Ake Edwardson, Kjell Eriksson, Asa Larsson, Stieg Larsson and Roslund & Hellstrom all have won this award (plus a whole host of writers who haven't made it across the Atlantic yet!)!
Both these a fore mentioned categories are awarded each year. However they do have two irregular categories - Best Swedish Debut and a Grand Master Award - which they give out only when they feel there is a deserving candidate.
(BTW - was not watching the calendar and posted this on Wednesday....*sigh*)