…amount of previous knowledge to the subject than certain dim recollections of two or three very long sums entered into a ciphering-book at school, and relieved for parental inspection by the effigy of a fat swan tastefully flourished by the writing-master’s own hand, he found himself, at the end of a fortnight, in a condition to report his proficiency to Mr Linkinwater, and to claim his promise that he, Nicholas Nickleby, should now be allowed to assist him in his graver labours.
There are no more uses of "proficiency" in the book.
Show samples from other sources
Not as well as my mother, but I’m pretty proficient."
Kiera Cass -- The Heir
Yvette was by far the most competent of my coworkers, and she and I would often work together on any electrical job requiring proficiency with tools.