Converting pounds to dollars, and allowing for inflation, Sir Humphrey's salary adjusts to over $231,000 in Oct. 2020.
Although this was the final episode of the show, in the published diaries of 'Yes Prime Minister', the previous episode, 'The National Education Service' is the last entry. This was because this episode ends with Hacker getting one over on Sir Humphrey, whereas in the previous episode, Sir Humphrey defeats Hacker's innovative education plan. The writers wanted the book to end with a passage where Hacker finally accepts that, despite the odd small triumph, he will never get the better of the Civil Service.
Last show of the series.