In Lansweeper 5.3, only the current state of the asset is stored in the database. The Lansweeper 6.0 beta does include a new database table (tblConfigLog) that logs changes made to the Configuration tab and to assets. I'm not sure whether you'll be able to identify state changes specifically and whether changes made by cleanup options are logged as well - the logging feature is still being worked on - but my 6.0 installation did add the following to the tblConfigLog table when I manually changed the state of an asset:
Altered asset with name 'DC2-WIN2008'. (Assets) 02/11/2016 16:55:31
If you haven't already, contact support@lansweeper.com and include "beta" in the title of your message. We'll add you to our list of beta testers and send you the beta.