| Año | Valor |
|---|---|
| 1981-01-01 | 5.435345 |
| 1982-01-01 | 5.555329 |
| 1983-01-01 | 5.676230 |
| 1984-01-01 | 5.798826 |
| 1985-01-01 | 5.922815 |
| 1986-01-01 | 6.048628 |
| 1987-01-01 | 6.177570 |
| 1988-01-01 | 6.309894 |
| 1989-01-01 | 6.444905 |
| 1990-01-01 | 6.581872 |
| 1991-01-01 | 6.720474 |
| 1992-01-01 | 6.858983 |
| 1993-01-01 | 6.996395 |
| 1994-01-01 | 7.133132 |
| 1995-01-01 | 7.269155 |
| 1996-01-01 | 7.404907 |
| 1997-01-01 | 7.539832 |
| 1998-01-01 | 7.674138 |
| 1999-01-01 | 7.809292 |
| 2000-01-01 | 7.944545 |
Fuente: World Bank