user: Question: What is the lowest official ITV1 rating with 45.4% share?
Columns: ['Episode', 'Air date', 'Official ITV1 rating', 'Weekly rank', 'Share']
Types: ['text', 'text', 'real', 'text', 'text']
Sample row: ['Auditions 1', '16 August', 10.78, '1', '48.2%']
SQL:

assistant: SELECT MIN("Official ITV1 rating") FROM "Table" WHERE "Share" = '45.4%';