I think some of us get the 18 shows (Mirage tour) because some of the members mostly Mick said so in his book or something. I never bothered to count them
There is a part in Mick's first book about touring for the 5 weeks Mirage was #1. When the tour was over Mirage fell like a rock from the charts. Mick said he wanted to stay out there and tour but Stevie and Christine had their own records scheduled so he was thankful for the 18 shows or something.
Bottom line, Mirage was an extremely short tour. I used to have the Mirage tour shirt and had the cities on back. I don't think there were more than 20 because they went down the middle of the shirt in fairly large lettering.