user: Question: What is the change (%) when the area size (km2) is 247.21?
Columns: ['Name', 'Municipal status', 'Census division', 'Population (2011)', 'Population (2006)', 'Change (%)', 'Area (km²)', 'Population density']
Types: ['text', 'text', 'text', 'real', 'real', 'text', 'text', 'text']
Sample row: ['Barrie', 'Single-tier', 'Simcoe', 136063.0, 128430.0, '5.9', '77.39', '1758.1']
SQL:

assistant: SELECT "Change (%)" FROM "Table" WHERE "Area (km²)" = '247.21';