| Año | Valor |
|---|---|
| 1991-01-01 | 11.479257 |
| 1992-01-01 | 1.597984 |
| 1993-01-01 | 22.406295 |
| 1994-01-01 | 18.243943 |
| 1995-01-01 | 22.023193 |
| 1996-01-01 | 31.314282 |
| 1997-01-01 | 16.338786 |
| 1998-01-01 | 22.468420 |
| 1999-01-01 | 31.711189 |
| 2000-01-01 | 33.392007 |
| 2001-01-01 | 38.503486 |
| 2002-01-01 | 44.260371 |
| 2003-01-01 | 39.159246 |
| 2004-01-01 | 69.538207 |
| 2005-01-01 | 60.088355 |
| 2006-01-01 | 65.962587 |
| 2007-01-01 | 78.822392 |
| 2008-01-01 | 67.253400 |
| 2009-01-01 | 65.803824 |
| 2010-01-01 | 117.608891 |
Fuente: World Bank