The issues in the series are annuals in name only. While it is uncertain as to exactly when each issue was published since none contain dates, what is certain is that they were not published annually. It appears that publisher Swan retained the word "annual" as it appeared on the covers of the American source issues.
Date based on when first mentioned in Archie (Gerald G. Swan, 1950 series) and promotion in 1952 albums. Issue #20 dated November 1958 according to promo in Archie (Gerald G. Swan, 1955 series) #11, so final issues in 1959.