What are the request rate limits on the Historical Data API?

The Historical Data API has a request rate limit of 100 requests in 10 seconds. 

Any requests that breach this limit will return a HTTP 429 Too Many Request error.

All of the below requests (including any errors returned) are included in the 100 requests limit.  All requests are summed up within a 10 second period.

• GetMyData - Returns the packages you have purchased
• GetCollectionOptions - Returns the filter options for a give filter
• DownloadListOfFiles - Returns a list of files based on a filter
• GetAdvBasketDataSize - Returns a file count and size based on a filter
• DownloadFile - Downloads a specific file