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 | Chassis | Engine | Start | Finish | Entrant |
| --- | --- | --- | --- | --- | --- |
| 1977.0 | Parnelli VPJ6B | Cosworth | 7 | 20 | Interscope Racing |
| 1978.0 | Parnelli VPJ6B | Cosworth | 2 | 18 | Interscope Racing |
| 1979.0 | Parnelli VPJ6C | Cosworth | 27 | 4 | Interscope Racing |
| 1980.0 | Parnelli VPJ6C | Cosworth | 16 | 7 | Interscope Racing |
| 1981.0 | Interscope 81 | Cosworth | 21 | 27 | Interscope Racing |
| 1982.0 | Interscope 03 | Cosworth | 9 | 22 | Interscope Racing |
| 1983.0 | March 83C | Cosworth | 21 | 21 | Interscope Racing |
| 1984.0 | March 84C | Cosworth | 11 | 9 | Interscope Racing |
| 1985.0 | March 85C | Cosworth | 17 | 17 | Interscope Racing |
| 1986.0 | March 86C | Buick | 16 | 23 | March Engineering |
| 1987.0 | Penske PC-16 | Chevrolet | Practice Crash 1 | Practice Crash 1 | Team Penske |
| 1996.0 | Lola T95/00 | Menard - Buick | 33 2 | 7 | Team Menard |
| 1998.0 | Dallara | Oldsmobile | DNQ | DNQ | Team Pelfrey |
Question:
What Engine has a Finish of 21?
Answer:
Cosworth