user: Question: How many hometowns are there when Charis Prep was the previous school?
Columns: ['Name', '#', 'Position', 'Height', 'Weight ( lb. )', 'Year', 'Hometown', 'Previous School']
Types: ['text', 'real', 'text', 'text', 'real', 'text', 'text', 'text']
Sample row: ['Karon Abraham Category:Articles with hCards', 4.0, 'Guard', 'ft9in (m)', 150.0, '2 Sophomore', 'Paterson , NJ', 'Paterson Eastside HS']
SQL:

assistant: SELECT COUNT("Hometown") FROM "Table" WHERE "Previous School" = 'Charis Prep';