SELECT "People's Party" FROM table_5595 WHERE "Social Democratic" = '30.1%'
Name the people's party for social democratic of 30.1%
CREATE TABLE table_5595 (
    "Date Released" text,
    "Institute" text,
    "Socialist" text,
    "Social Democratic" text,
    "Green-Communist" text,
    "Left Bloc" text,
    "People's Party" text,
    "Lead" text
)