Different between month balance in 3 , 12 monthes

i have a big different between Balance at end of March when use last 3 month period , and Balance at end of March when use last 12 month period , is this normal

 

Ya this is normal because last 3 months period shows only the earnings in last 3 months while earnings in last 12 months shows earnings in last 12 months that include even the last 3 months.