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:
| House Name | Composition | Named after | Founded | Colours |
| --- | --- | --- | --- | --- |
| Benue | Coed | River Benue | 1973.0 | Yellow |
| Gongola | Coed | Gongola River | 1980.0 | Purple |
| Niger | Coed | River Niger | 1973.0 | Green |
| Rima | Coed | Rima River | 1980.0 | Brown |
| Ogun | Coed | Ogun River | 1980.0 | Blue |
| Cross | Coed | Cross River | 1976.0 | Red |
Question:
When is the earliest year founded for houses named after the river benue?
Answer:
1973.0