?????????? yu want us tu inklude that start month (Jan 1855) ???????????
55 tu 59=4 yeers
most kommon wae...june=6, Jan =1, so from Jan tu June=6-1=5months
so yer time span=4 yrs+5 months=48+5=53 months
312,876 / 53=5,870.093809
or bout 5870 per month