I have a query related to the absences I or my wife can have, before applying for ILR.

I have explained the whole scenario.

I am holding Tier 1 General visa
Visa details
Issue date : 30th Oct 2008
Expiry date : 30th Oct 2011

I have entered UK for the first time on 14th Sept 2009 (nearly about 10 months after getting the visa). Hence, I will be needing two extensions to cover the 5 year period requirement to apply for ILR. Till today, I had been to India 4 times in various intervals.
May 2010 : 9 days
July 2010 : 8 days (My engagement)
29th Oct 2010 - 15th Jan 2011 : 78 days (My mother was hospitalised…expired in this period)
Apr 2011 : 12 days (To help my wife applying the dependant visa)

For 2010 : around 80 days outside UK
For 2011 : around 27 days outside UK till now

Making a total of 107 days (from 14th Sept 2009 till today).

My query here is regarding the no of absences I (and my wife) can have outside UK. My wife is going to join me from 27th May 2011 (coming friday). I tried searching the web but couldnt get anything specific to it.

Is there any criteria that per year or per 5 years I can have only limited no of absences out of UK? Does the question applies to me only or for my wife too?

Kindly tell me the absences criteria to meet the ILR requirement (out of UK) so that I can plan better to apply for ILR (that is after about three years).

Any kind of information would be great help to me.

Thanks in advance.

Regards
Tajinder