I was wondering when do you guys recommend replacing battery?

Notice how the design is almost 50% less than the full charge? I was just thinking maybe I should place an order for a new battery on amazon or ebay but I wanted to run things by you guys... the professions!

Here is a snippet of the generated report for Battery capacity history for my Dell Latitude 7390 Laptop:

FULL CHARGE CAPACITY	DESIGN CAPACITY
60,002 mWh	34,071 mWh

	BATTERY 1
NAME	DELL DM3WC64
MANUFACTURER	SMP
SERIAL NUMBER	532
CHEMISTRY	LiP
DESIGN CAPACITY	60,002 mWh
FULL CHARGE CAPACITY	34,071 mWh
CYCLE COUNT	-