user: Question: What is the average population in 1991, that has a 2001 population less than 16045, and a rank less than 58, in Eisenstadt?
Columns: ['Rank', 'Name', 'Population 1991', 'Population 2001', 'Population 2007', 'State']
Types: ['real', 'text', 'real', 'real', 'real', 'text']
Sample row: [1.0, 'Vienna', 1539848.0, 1550123.0, 1664146.0, 'Vienna']
SQL:

assistant: SELECT AVG("Population 1991") FROM "Table" WHERE "Population 2001" < 16045.0 AND "Rank" < 58.0 AND "Name" = 'Eisenstadt';