SELECT "% Buddhist" FROM table_46894 WHERE "Population" = '~2.6 million (2.6million)'
What is the percentage of Buddhist when the Population is ~2.6 million (2.6million)?
CREATE TABLE table_46894 (
    "Area" text,
    "Population" text,
    "% Muslim" text,
    "% Hindu" text,
    "% Buddhist" text,
    "% Other" text
)