SELECT "population\ncenter" FROM table_203_729 WHERE "township" = 'green garden'
what is the only population center in the green garden township ?
CREATE TABLE table_203_729 (
    id number,
    "township" text,
    "fips" number,
    "population\ncenter" text,
    "population" number,
    "population\ndensity\n/km2 (/sq mi)" text,
    "land area\nkm2 (sq mi)" text,
    "water area\nkm2 (sq mi)" text,
    "water %" text,
    "geographic coordinates" text
)