That is not true. Star wars is an exception and the cut percentage increased by 1%. The real reason is the dropping viewership. Number of tickets sold peaked in 2012. Beyond that the number of movie tickets sold dropped, however number of locations is up and salaries have gone up. To compensate for it, movie ticket prices need to go up.
Yes, it increased by 1% from 'The Force Awakens', which was last year (edit: 2 years ago, time flies) and also obscenely high. Don't say my statement is 'not true' then confirm it in the next sentence.