you can get a list of builds, for example /app/rest/builds/?locator=buildType:<conf id>
, extract the id and get the artifacts of this build
/app/rest/builds/id:<buildID>/artifacts/children/
<files count="1">
<file name="result.zip" size="73785398" modificationTime="20190617T162953+0000" href="/app/rest/builds/id:45771/artifacts/metadata/result.zip">
<content href="/app/rest/builds/id:45771/artifacts/content/result.zip"/>
</file>
</files>
as you can see, I collect all files to result.zip, let's extract this ZIP and see what is inside
/app/rest/builds/id:<buildID>/artifacts/children/result.zip/
<files count="2">
<file name="bin" modificationTime="19700101T000000+0000" href="/app/rest/builds/id:45771/artifacts/metadata/result.zip%21/bin">
<children href="/app/rest/builds/id:45771/artifacts/children/result.zip%21/bin"/>
</file>
<file name="yaml" modificationTime="19700101T000000+0000" href="/app/rest/builds/id:45771/artifacts/metadata/result.zip%21/yaml">
<children href="/app/rest/builds/id:45771/artifacts/children/result.zip%21/yaml"/>
</file>
</files>
So, you can collect the specific builds, by last month, by status.
You can collect the artifacts pats for each build.
And you able to aggregate all results as you want.