work experience letter - content length for 15 month

[kseekba27]

Hello friends,
what do you think is the average in terms of no# of bullet points you can come up with for 15month stint?
I had multiple roles and was a individual performer reporting to my boss.
I mean i neither want to be verbose nor fall short.

Thanks much!

 

[kseekba27]

thanks @eng.ahamdi