Getting the version of a crystal report in code

I have a program which reads all our crystal reports and summarises certain information for each report, e.g. number of sub-reports, connection type, number of parameters etc.

What I would like it to do is also get the version of Crystal Reports that created this particular report.

Any idea where that information is hiding? I can't find it.

I'm loading the report into CrystalDecisions.CrystalReports.Engine.ReportDocument and have scoured the various properties therein to no avail.