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:
| Year | Result | World Rank | Location | Date |
| --- | --- | --- | --- | --- |
| 1972.0 | 20.2 | 3rd | El Paso | Apr 15 |
| 1973.0 | 20.33 | 1st | Bakersfield | Jun 16 |
| 1974.0 | 20.2 | 4th | Viareggio | Aug 7 |
| 1975.0 | 19.8 | 1st | Eugene | Jun 7 |
| 1976.0 | 19.9 | 2nd | Gainesville | Apr 17 |
| 1977.0 | 20.31 | 5th | Kingston | May 13 |
| 1978.0 | 20.26 | 6th | Zurich | Aug 16 |
| 1980.0 | 20.26 | 5th | Brussels | Aug 22 |
Question:
What Year has a Result smaller than 20.31, and a World Rank of 5th?
Answer:
1980.0