how many more silver medals did gillis grafstr m have compared to sonja henie ?
CREATE TABLE table_203_104 (
    id number,
    "athlete" text,
    "nation" text,
    "olympics" text,
    "gold" number,
    "silver" number,
    "bronze" number,
    "total" number
)
SELECT (SELECT "silver" FROM table_203_104 WHERE "athlete" = 'gillis grafstrom') - (SELECT "silver" FROM table_203_104 WHERE "athlete" = 'sonja henie')
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: how many more silver medals did gillis grafstr m have compared to sonja henie ? ### Input: CREATE TABLE table_203_104 (
    id number,
    "athlete" text,
    "nation" text,
    "olympics" text,
    "gold" number,
    "silver" number,
    "bronze" number,
    "total" number
) ### Response: SELECT (SELECT "silver" FROM table_203_104 WHERE "athlete" = 'gillis grafstrom') - (SELECT "silver" FROM table_203_104 WHERE "athlete" = 'sonja henie')