Pakistan's blasphemy laws -- especially the notorious Section 295(c) of the Penal Code -- are often used against religious minorities to settle personal scores. So the number of Christians charged is disproportionate.
Under a 1990 ruling, a guilty verdict should mean the death penalty: in practice, there have been no official executions for blasphemy to date. Courts have tended to give a life sentence, though it is often reduced on appeal.
[Information from Release International.]
You will not find a great deal about this on the website of Amnesty. They seem to me to be extremely selective about whom they seriously attack.
