I have a chart that I've created. The X-axis lables look like this:

29 6 13 20 27
October

I would like to put an average underneath "October." I have a row that
calculates averages for each month. I have been able to go in and manually
add a hard return to my "October" title so that it shows up like this:

October
(4.2)

I created the following formula to have that average automate itself, so I
don't have to manually change the averages of the data for each month. The
formula looks like this (my average is in cell D2).

="October"&"("D2&")

However, this shows up like this:

October(4.2)

How do I write the formula to add a hard return so that the "4.2" is
centered underneath the "October"?

Thank you!