Table schema:
CREATE TABLE table_25983027_1 (rainfall_by_depth__mm_year_ VARCHAR, land_area__km_2__ VARCHAR)

Question: In the Central region, where the land area (km 2) is 8,543.2, what was the rainfall by depth (mm/year)?
SQL: SELECT rainfall_by_depth__mm_year_ FROM table_25983027_1 WHERE land_area__km_2__ = "8,543.2"