user: Question: What is the average Isolation in the municipality of sunndal at an elevation of more than 1850?
Columns: ['Peak', 'Elevation (m)', 'Prominence (m)', 'Isolation (km)', 'Municipality', 'County']
Types: ['text', 'real', 'real', 'real', 'text', 'text']
Sample row: ['Galdhøpiggen', 2469.0, 2372.0, 1570.0, 'Lom', 'Oppland']
SQL:

assistant: SELECT AVG("Isolation (km)") FROM "Table" WHERE "Municipality" = 'sunndal' AND "Elevation (m)" > 1850.0;