CREATE TABLE table_64746 ("Rank" TEXT, "Province" TEXT, "Population  ( 2011 ) " FLOAT, "Percentage" FLOAT, "Population Estimate  ( 2013 ) " FLOAT)

What is the lowest 2013 population estimate of the province with a 23.7 percentage?
SELECT MIN("Population Estimate (2013)") FROM table_64746 WHERE "Percentage" = '23.7'
SELECT MIN("Population Estimate (2013)") FROM "table_64746" WHERE "Percentage" = '23.7'