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:
| City | 1970 | 1980 | 1990 | 2000 | 2010 est. |
| --- | --- | --- | --- | --- | --- |
| Cedar Hill | 2610.0 | 6849.0 | 19988.0 | 32093.0 | 46300.0 |
| DeSoto | 6617.0 | 15538.0 | 30544.0 | 37646.0 | 49600.0 |
| Duncanville | 14105.0 | 27781.0 | 35008.0 | 36081.0 | 39250.0 |
| Lancaster | 10522.0 | 14807.0 | 22117.0 | 25894.0 | 36600.0 |
| Total | 33854.0 | 64975.0 | 107657.0 | 131714.0 | 171750.0 |
Question:
With 1990 growth greater than 19,988 and 1970 growth less than 10,522, what is the 1980 average?
Answer:
15538.0