| Año | Valor |
|---|---|
| 1980-01-01 | 0.000729 |
| 1981-01-01 | 0.000944 |
| 1982-01-01 | 0.002438 |
| 1983-01-01 | 0.008904 |
| 1984-01-01 | 0.137427 |
| 1985-01-01 | 17.094030 |
| 1986-01-01 | 56.428286 |
| 1987-01-01 | 64.657896 |
| 1988-01-01 | 75.988118 |
| 1989-01-01 | 86.008231 |
| 1990-01-01 | 100.000000 |
| 1991-01-01 | 117.689440 |
| 1992-01-01 | 133.223510 |
| 1993-01-01 | 141.959186 |
| 1994-01-01 | 153.248076 |
| 1995-01-01 | 170.760165 |
| 1996-01-01 | 190.534545 |
| 1997-01-01 | 201.404624 |
| 1998-01-01 | 215.605919 |
| 1999-01-01 | 220.805398 |
Fuente: World Bank