-----------------------+-----------------------+-----------------------
In 1810. | In 1820. | In 1830.
-------+-------+-------+-------+-------+-------+-------+-------+-------
Free | Slave | Total | Free | Slave | Total | Free | Slave | Total
-------+-------+-------+-------+-------+-------+-------+-------+-------
20 | 9 | 19 | 24 | 10 | 21 | 24 | 10 | 22
-------+-------+-------+-------+-------+-------+-------+-------+-------