I don’t know a method for tracking statements through time in Subversion.
It is simple however to see when any particular line in a file was last changed using svn blame. Check the SVNBook: svn blame reference:
Synopsis
svn blame TARGET[@REV]...
Description
Show author and revision information in-line for the specified files or URLs. Each line of text is annotated at the beginning with the author (username) and the revision number for the last change to that line.