 For the group with 1.79% population in 1961, what was their percentage of the population in 1971?
CREATE TABLE table_4506 (
    "Religious group" text,
    "Population % 1961" text,
    "Population % 1971" text,
    "Population % 1981" text,
    "Population % 1991" text,
    "Population % 2001" text
)
SELECT "Population % 1971" FROM table_4506 WHERE "Population % 1961" = '1.79%'