Jan ( N = 310 )
Feb ( N = 290 )
Mar ( N = 300 )
Apr ( N = 247 )
May ( N = 290 )
Jun ( N = 230 )
Jul ( N = 310 )
Aug ( N = 310 )
Sep ( N = 280 )
Oct ( N = 300 )
Nov ( N = 240 )
Dec ( N = 310 )