Basically what happens is that the employment benefits plan is based on the actual salary you forecast. As well, it's also based on a percentage that's pre-established by Treasury Board. In previous years it was 20%. This year it went down to 19%, so it's an adjustment.
Evidence of meeting #14 for Access to Information, Privacy and Ethics in the 39th Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was budget.
A recording is available from Parliament.