Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Rank Subcontinent | Rank Asia | Rank World | Country | 2011 GDP (PPP) billions of USD |
| --- | --- | --- | --- | --- |
| 1.0 | 2.0 | 3.0 | India | $4,469.763 |
| 2.0 | 11.0 | 27.0 | Pakistan | $489.436 |
| 3.0 | 17.0 | 42.0 | Bangladesh | $282.945 |
| 4.0 | 25.0 | 65.0 | Sri Lanka | $115.220 |
| 5.0 | 34.0 | 96.0 | Nepal | $37.799 |
| 6.0 | 38.0 | 106.0 | Afghanistan | $30.012 |
| 7.0 | 46.0 | 155.0 | Bhutan | $4.285 |
| 8.0 | 49.0 | 164.0 | Maldives | $2.735 |
Question:
Name the rank world for 7 rank subcontinent
Answer:
155.0