Yes, there is, here my though:
Using a program with Erlang B Model:
G.O.S = 0.01
Traffic for 30 E0s= 1240 BHmin.
Here some average data:
Busydays per month= 25 (México)
Busy Hour (heavy hour in one busy day) represents aprox 11% (México)
Then:
1240 min/0.11 = 11272 min per day
11272 min * 25 dys = 281,818 minutes per month supported.