Traci, your posts got caught by our spam filter, which is why we didn’t see them. In the link you sent it looks like you were already able to remove the zeros from the “immigrate-year” column. Are you all set now?
P.S. another way to do what you wanted to do would have been to drag the immigrate-year attribute all the way to the left in the table, creating groupings by immigrate-year. You could then change “0” to blank or whatever you want, and then move the attribute back to where it was.