List the number of invoices from the US, grouped by state.
SELECT billing_state ,  COUNT(*) FROM invoices WHERE billing_country  =  "USA" GROUP BY billing_state;
SELECT billing_state ,  COUNT(*) FROM invoices WHERE billing_country  =  "USA" GROUP BY billing_state;
[{'billing_state': 'AZ', 'COUNT(*)': 7}, {'billing_state': 'CA', 'COUNT(*)': 21}, {'billing_state': 'FL', 'COUNT(*)': 7}, {'billing_state': 'IL', 'COUNT(*)': 7}, {'billing_state': 'MA', 'COUNT(*)': 7}, {'billing_state': 'NV', 'COUNT(*)': 7}, {'billing_state': 'NY', 'COUNT(*)': 7}, {'billing_state': 'TX', 'COUNT(*)': 7}, {'billing_state': 'UT', 'COUNT(*)': 7}, {'billing_state': 'WA', 'COUNT(*)': 7}, {'billing_state': 'WI', 'COUNT(*)': 7}]