| Año | Valor |
|---|---|
| 1985-01-01 | 9.826057 |
| 1986-01-01 | 13.147574 |
| 1987-01-01 | 13.023821 |
| 1988-01-01 | 12.497339 |
| 1989-01-01 | 12.750213 |
| 1990-01-01 | 13.675331 |
| 1991-01-01 | 14.850935 |
| 1992-01-01 | 15.171705 |
| 1993-01-01 | 16.041968 |
| 1994-01-01 | 16.386394 |
| 1995-01-01 | 16.236352 |
| 1996-01-01 | 17.167756 |
| 1997-01-01 | 16.977530 |
| 1998-01-01 | 17.683658 |
| 1999-01-01 | 17.898432 |
| 2000-01-01 | 17.801980 |
| 2001-01-01 | 16.908319 |
| 2002-01-01 | 18.377052 |
| 2003-01-01 | 18.795735 |
| 2004-01-01 | 20.242405 |
Fuente: World Bank