Things we don't currently allow the client to filter by, but Technically Support.

[ethantmc]

For Usages:
Unit: (valid values only include 'Percent')
Value:

For Responses:
Estimate: 'Number of persons', 'Percentage of persons', 'Low 95% confidence interval, percent', 'High 95% confidence interval, percent'
Unit: 'Persons', 'Percent'
Value:

Should we? If not, we can omit Unit and Estimate from frontend.js searches. We may still access them for charting purposes.