Endpoint for frequency and ridership scatterplot

[jaronheard]

Would like an endpoint to be very similar to the properties on this GeoJSON, but please deliver as JSON without geometries.

http://service.civicpdx.org/transportation-systems/passenger-census/routes/change/

        "properties": {
          "route_id": "115",
// please aggregate by direction
          "direction_id": 0,
// need these three datapoints below for ridership
          "y2009_trip_count": 31271,
          "y2017_trip_count": 0,
          "pct_change": -100
// something like
          "y2009_annual_ons": 31271,
          "y2017_annual_ons": 0,
          "ons pct_change": -100
        }