If the language is only native, what is the percentage of the San Antonio de Lomerio municipality?
create table table_19998428_3 (san_antonio_de_lomerío_municipality___percentage_ varchar, language varchar, PRIMARY KEY (san_antonio_de_lomerío_municipality___percentage_))
select san_antonio_de_lomerío_municipality___percentage_ from table_19998428_3 where language = "only native"