I want to know the answer to the following question:
When did the dominant religion of Myanmar become something outside of the mainstream ?
All the background I'm provided with is that "In the 9th century, the Bamar people entered the upper Irrawaddy valley and, following the establishment of the Pagan Kingdom in the 1050s, the Burmese language, culture and Theravada Buddhism slowly became dominant in the country.". Is that enough to answer the question?
Answer: yes