user: Question: What is the length  (miles) when Pico to 7th St/Metro Center are the endpoints?
Columns: ['Segment description', 'Date opened', 'Line(s)', 'Endpoints', '# of new stations', 'Length (miles)']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Blue Line Initial Segment', 'July 14, 1990', 'Blue', 'Pico to Anaheim Street', '17', '19.1']
SQL:

assistant: SELECT "Length (miles)" FROM "Table" WHERE "Endpoints" = 'Pico to 7th St/Metro Center';