Hi @Hannah,
1. Enable CloudTrail logging for your account in the US East region
2. Once your trails are written to S3, create a table for the logs
3. Open Athena console and add the following query to the query box
SELECT apiversion, count() AS Total FROM $databaseName.$tableName WHERE eventsource = 'cloudfront.amazonaws.com' AND parse_datetime(apiversion, 'yyyy_MM_dd') <= parse_datetime('2015_12_22', 'yyyy_MM_dd') GROUP BY apiversion ORDER BY Total Desc;