user: Question: For how many games on December 19 is there information on who scored the most rebounds?
Columns: ['Game', 'Date', 'Team', 'Score', 'High points', 'High rebounds', 'High assists', 'Location Attendance', 'Record']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [20.0, 'December 3', 'Orlando', 'L 91–104 (OT)', 'Tayshaun Prince (30)', 'Ben Gordon (9)', 'Rodney Stuckey (7)', 'The Palace of Auburn Hills 18,433', '6–14']
SQL:

assistant: SELECT COUNT("High rebounds") FROM "Table" WHERE "Date" = 'December 19';