This is just a guess btw, but there is room for two more gigs between Tampere and Wacken. One between Tampere and Bergen. That's gonna be either a second night in Tampere, or maybe Stockholm. There are no clear rumours what they will do in this gap, but possibly two nights in Tampere.33 gigs.
The second is between Krakow and Zürich. This one is almost certainly Hellfest on the 17th of June.
That brings us to 30 shows. So the question is how many they do before Tampere. There is a rumour on the fanclub Maiden will start in Aalborg, and another that they will play Stockholm on the first of June, however it's not certain. I think we might know more on Thursday.