Search Volume for Keyword

[Aditya]

I know that TargetingIdeaService can be used to start with a list of seed keywords, which will then return a list of new keyword ideas (and then you can get search volume for those new keywords). Is there a way to get the search volume for the initial seed keywords? Either historical or estimated search volume... I know that the actual keyword planner tool on the website allows you to see this information, but I can't tell if there's an API service that will allow us to retrieve this.

Basically, if I have a keyword, how do I get the search volume for it through the API? And as a followup, is there a way to do this using reports (or would be basically have to do this query on a keyword by keyword level?). I only ask that followup so I can figure out if we'll hit our API limit if we search for a big list of words. 

Thanks so much!

[Aditya]

I guess it looks like TrafficEstimatorService is essentially what I want. But when I get the min and max stats objects (keywordEstimate.getMin().getXYZ() as in the EstimateKeywordTraffic.java example), I'm a little confused on how to get search volume. Is getImpressionsPerDay what I want if I'm looking for search volume?