| Año | Valor |
|---|---|
| 1991-01-01 | 10.155662 |
| 1992-01-01 | 11.069498 |
| 1993-01-01 | 13.008874 |
| 1994-01-01 | 15.979030 |
| 1995-01-01 | 18.761546 |
| 1996-01-01 | 24.673776 |
| 1997-01-01 | 25.579324 |
| 1998-01-01 | 21.427885 |
| 1999-01-01 | 22.078634 |
| 2000-01-01 | 20.094271 |
| 2001-01-01 | 23.905165 |
| 2002-01-01 | 17.480480 |
| 2003-01-01 | 18.705926 |
| 2004-01-01 | 20.231195 |
| 2005-01-01 | 25.761730 |
| 2006-01-01 | 51.056605 |
| 2007-01-01 | 104.913345 |
| 2008-01-01 | 135.409788 |
| 2009-01-01 | 148.340759 |
| 2010-01-01 | 168.452802 |
Fuente: World Bank