| Año | Valor |
|---|---|
| 1970-01-01 | 0.000400 |
| 1971-01-01 | 0.000400 |
| 1972-01-01 | 0.000500 |
| 1973-01-01 | 0.000500 |
| 1974-01-01 | 0.000500 |
| 1975-01-01 | 0.000600 |
| 1976-01-01 | 0.000700 |
| 1977-01-01 | 0.000700 |
| 1978-01-01 | 0.000800 |
| 1979-01-01 | 0.000900 |
| 1980-01-01 | 0.001100 |
| 1981-01-01 | 0.001200 |
| 1982-01-01 | 0.001100 |
| 1983-01-01 | 0.001100 |
| 1984-01-01 | 0.001100 |
| 1985-01-01 | 0.001000 |
| 1986-01-01 | 0.001100 |
| 1987-01-01 | 0.001300 |
| 1988-01-01 | 0.001400 |
| 1989-01-01 | 0.001500 |
Fuente: World Bank