user: Question: What is the measurement where the estimated function % is less than 20?
Columns: ['Grade', 'Description', 'Measurement', 'Function %', 'Estimated function %']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['I', 'Normal', '8/8', '100', 100.0]
SQL:

assistant: SELECT "Measurement" FROM "Table" WHERE "Estimated function %" < 20.0;