Bear in mind that Erlang B is theory.
For example a long term average 2% blocking in a cell can mean 0% for 4 days then 10% on Friday!
You will also find that blocking in low capacity cells doesn’t follow Erlang B (or Erlang C) – why? because it’s not random. An extreme example, say, in a conference hall, everone will try make a call at the end of the presentation. So you get blocking even though the average traffic is much lower than what Erlang B predicts.
So, be-aware of using Erlang B for capacity planning on small numbers of circuits.