Jan ( N = 310 )
Feb ( N = 280 )
Mar ( N = 310 )
Apr ( N = 300 )
May ( N = 310 )
Jun ( N = 300 )
Jul ( N = 305 )
Aug ( N = 228 )
Sep ( N = 259 )
Oct ( N = 304 )
Nov ( N = 300 )
Dec ( N = 300 )