user: Question: Name the total number of district for population may being 478
Columns: ['Barangay', 'District', 'Population (May 1, 2000)', 'Population (August 1, 2007)', 'Population (May 1, 2010)']
Types: ['text', 'text', 'real', 'real', 'text']
Sample row: ['Agdeppa', 'Ag-Na', 976.0, 1110.0, '1,148']
SQL:

assistant: SELECT COUNT("District") FROM "Table" WHERE "Population (May 1, 2010)" = '478';