| Año | Valor |
|---|---|
| 1997-01-01 | 19.824605 |
| 1998-01-01 | 15.903465 |
| 1999-01-01 | 13.012127 |
| 2000-01-01 | 10.425102 |
| 2001-01-01 | 9.336201 |
| 2002-01-01 | 6.383253 |
| 2003-01-01 | 5.576835 |
| 2004-01-01 | 6.276284 |
| 2005-01-01 | 5.459804 |
| 2006-01-01 | 6.122784 |
| 2007-01-01 | 8.076210 |
| 2008-01-01 | 8.059854 |
| 2009-01-01 | 8.826184 |
| 2010-01-01 | 8.977462 |
| 2011-01-01 | 8.749646 |
| 2012-01-01 | 8.073688 |
| 2013-01-01 | 8.274563 |
| 2014-01-01 | 7.446519 |
| 2015-01-01 | 6.449325 |
| 2016-01-01 | 5.532914 |
Fuente: World Bank