It covers applicants who have applied for any course, including courses with an October deadline (statistics for those applying to October deadline courses can be viewed here).
It’s worth considering that interim releases are not designed for cycle to cycle comparisons as there is no secure way to get a like for like comparison point outside of scheme deadlines. However, for context purposes only interim releases do contain figures from previous cycles at an approximately similar reference point. This is normally taken as the third Monday in the month. But, for the 2016 cycle this reference point was unusually late in the month, after the closure of most schools, making the context of previous cycles of reduced value. Accordingly the reference point to capture activity in December has been moved to the first Monday in January which provides more suitable approximate context for applications received in December.
Figures published after the 15 January UCAS application deadline will provide the first reliable indication of general demand for higher education this cycle.