user: Question: What is the appearance maximum if the starts is 18?
Columns: ['Name', 'Nationality', 'Position', 'Sky Blue FC career', 'Appearances', 'Starts', 'Minutes', 'Goals', 'Assists']
Types: ['text', 'text', 'text', 'text', 'real', 'real', 'real', 'real', 'real']
Sample row: ['Cori Alexander Category:Articles with hCards', 'United States', 'GK', '2009', 0.0, 0.0, 0.0, 0.0, 0.0]
SQL:

assistant: SELECT MAX("Appearances") FROM "Table" WHERE "Starts" = 18.0;