Given the task definition and input, reply with output. This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

For the salary year beginning April 2008, unpromoted teachers in Scotland earned from 20,427 for a Probationer, up to 32,583 after 6 years teaching, but could then go on to earn up to 39,942 as they complete the modules to earn Chartered Teacher Status (requiring at least 6 years at up to two modules per year.) Promotion to Principal Teacher positions attracts a salary of between 34,566 and 44,616; Deputy Head, and Head teachers earn from 40,290 to 78,642. Teachers in Scotland can be registered members of trade unions with the main ones being the Educational Institute of Scotland and the Scottish Secondary Teachers' Association.
What is the start of the salary year?