question: What is the municipality percentage for San Antonio de Lomerio is San Javier municipality percentage is 31?
answer: SELECT san_antonio_de_lomerío_municipality___percentage_ FROM table_19998428_3 WHERE san_javier_municipality___percentage_ = 31
context: CREATE TABLE table_19998428_3 (san_antonio_de_lomerío_municipality___percentage_ VARCHAR, san_javier_municipality___percentage_ VARCHAR)