Iphone 5 battery charging and draining by jumping percentages.

I have iphone 5 with,
8.4.1 Ios Version , ,

i have serious problem with its battery, while charging from its original charger, it charges by jumping battery percentage,
it charges till 9% then jumps to 11%

again charge dill 21% and then jumps to 23%

again charge till 26% and jumps to 28%

charge till 29% and jumps to 31%

charge till 33% and jumps to 35%

charge till 39 % and jumps to 41%

charge till 43% and jumps to 45%

charges till 51% and jumps to 53%

it continues to doing this during full charging,

and while draining,

it does the same jumping,

for example.
31% to direct 29 %

28% to direct 26%

etc.

i am very worried about this,
is there any solution to charge missing points and utilize them.?

please help me...
Thank You.