user: Question: What is the first year where the assassination attempt was at Martyrs' Mausoleum, Rangoon, Burma?
Columns: ['Year', 'Date', 'Intended Victim(s)', 'Title at the Time', 'Location', 'Would-be Assassin(s)', 'Method', 'Initial Outcome / Notes']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1990.0, 'Apr 25', 'Oskar Lafontaine', 'Minister-President of Saarland', 'Cologne , West Germany', 'A deranged woman, Adelheid Streidel.', 'Knife attack', 'Serious neck wound']
SQL:

assistant: SELECT MIN("Year") FROM "Table" WHERE "Location" = 'Martyrs'' Mausoleum, Rangoon, Burma';