| Mes-Año | Precio |
|---|---|
| 12-2011 | $29.88 |
| 11-2011 | $29.35 |
| 10-2011 | $29.37 |
| 09-2011 | $29.08 |
| 08-2011 | $29.41 |
| 07-2011 | $29.76 |
| 06-2011 | $29.63 |
| 05-2011 | $29.39 |
| 04-2011 | $28.95 |
| 03-2011 | $28.60 |
| 02-2011 | $28.38 |
| 01-2011 | $28.10 |
| 12-2010 | $28.24 |
| 11-2010 | $28.07 |
| 10-2010 | $28.70 |
| 09-2010 | $28.35 |
| 08-2010 | $28.28 |
| 07-2010 | $27.11 |
| 06-2010 | $28.46 |
| 05-2010 | $28.52 |
Fuente: elaborado con datos de PROFECO.