SELECT MIN("Population (Mareeba)") FROM table_72315
What was the smallest population figure for Mareeba?
CREATE TABLE table_72315 (
    "Year" real,
    "Population (Region total)" real,
    "Population (Mareeba)" real,
    "Population (Atherton)" real,
    "Population (Herberton)" real,
    "Population (Eacham)" real
)