When you backup Imported Items using Amazing Backup, you overwrite the old folder.
Let me correct my statement above, which is wrong. When using Amazing Backup to backup Imported Items, you create a completely new .enc file with the title "practice name_acct_date_time.enc". This is found in the C:/Programs/AmazingCharts/Backups as well as the designated backup location, and does not overwrite the previous backup, which has a different date & time stamp. Sorry for the misinformation.