Hi Colby,
To do this, you'll just need to create a smart list with any activities which you want to consider as a Touch, like Email was Sent, Filled Out Form...etc. and set each asset to 'Is Any' and the Date of Activity to In Past 9 Months. When you've done this, set the filter logic to 'Is Any' and the list will include all of the records which have performed any of these in the specified time frame.