ILR and finance question

[sidira]

My ILR is due in Feb 2012. I have been here on HSMP initially for 2 years and then Tier 1 for last 3 years. My question is what are the finance requirements for ILR? I have been in permanent job since the beginning but planning to switch into contracting. By this there may be a gap of few weeks when I will not earn (notice period and then contract start etc).
Do they consider continuous earnings all through out 5 years or at least last 12 months? Or do they see average earnings of last 5 years? Or just last 3 months as they ask for only those salary slips?

Thanks, S