user: Question: How many counties are at milepost 69.5? 
Columns: ['County', 'Town/City', 'Milepost', 'Station', 'Connections']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Fairfield', 'Stratford', '59.0', 'Stratford (Limited service)', 'Shore Line East GBTA : 1, 10, 16, 23, Coastal Link']
SQL:

assistant: SELECT COUNT("County") FROM "Table" WHERE "Milepost" = '69.5';