| Año | Valor |
|---|---|
| 1996-01-01 | 33.547032 |
| 1997-01-01 | 19.824605 |
| 1998-01-01 | 21.410891 |
| 1999-01-01 | 28.449689 |
| 2000-01-01 | 20.668899 |
| 2001-01-01 | 22.807435 |
| 2002-01-01 | 27.088392 |
| 2003-01-01 | 35.524931 |
| 2004-01-01 | 37.007591 |
| 2005-01-01 | 36.310284 |
| 2006-01-01 | 35.510490 |
| 2007-01-01 | 42.202098 |
| 2008-01-01 | 36.572684 |
| 2009-01-01 | 38.745782 |
| 2010-01-01 | 43.761260 |
| 2011-01-01 | 40.041629 |
| 2012-01-01 | 52.816737 |
| 2013-01-01 | 47.263888 |
| 2014-01-01 | 55.209404 |
| 2015-01-01 | 56.253280 |
Fuente: World Bank