Jan ( N = 21 )

Feb ( N = 28 )

Mar ( N = 31 )

Apr ( N = 29 )

May ( N = 29 )

Jun ( N = 30 )

Jul ( N = 31 )

Aug ( N = 30 )

Sep ( N = 30 )

Oct ( N = 29 )

Nov ( N = 29 )

Dec ( N = 27 )