user: Question: Of 2010 est. with less than 171750 and 2000 less than 131714, what is the 1970 population average?
Columns: ['City', '1970', '1980', '1990', '2000', '2010 est.']
Types: ['text', 'real', 'real', 'real', 'real', 'real']
Sample row: ['Cedar Hill', 2610.0, 6849.0, 19988.0, 32093.0, 46300.0]
SQL:

assistant: SELECT AVG("1970") FROM "Table" WHERE "2010 est." = 171750.0 AND "2000" < 131714.0;