I feel it is valid, as Bobad proposes in his post of Nov8, to add together the alternative spellings of what is essentially the same name.

As Dave mentions Mohammed is ranked 22 by the DNS, but Muhammad is also there at 44. Someone do the sums please, I've gone off arithmetic.

Just as an aside; Mohammed seems to have been pretty consistent, rankings for 2002-6 being 22,22,20,23,and 22.

I suspect the explanation is as Dave suggests: that a high proportion of male moslems have one variation or the other as their first name. That would certainly fit with my experience when working in Bradford with a large customer base among the whole community [almost everyone of working age needs a bank account].