How many weeks of NI contribution to count as Qualifying Year

[buildersmate]

How many weeks of NI contribution (or NI credit) are required out of 52 maximum for that year to count as a 'Qualifying Year'? It's very easy to find out how many qualifying years are required for a full Basic State Pension entitlement. HMRC seem less forthcoming when asked the question, how many weeks constitute an entitlement to one specific Qualifying Year. The verbal answer given is 52 - I suspect it may be a few less. Anyone know please?

[kempie]

Qualifying years are determined by the amount earned in that tax year, not how many weeks it took to cross the threshold.

From the Pension Service guide to State Pensions [NP46]...

A qualifying year for the basic State Pension is a tax year in which you have received (or are treated as having received) qualifying earnings of at least 52 times the Lower Earnings Limit for that year.

Between 6 April 1975 and 5 April 1978, the qualifying earnings needed in a tax year for it to be a qualifying year were 50 times the Lower Earnings Limit for that year.

http://www.thepensionservice.gov.uk/pdf/np46/n p46apr05.pdf

A bit of hunting is required to ascertain the LELs which are applicable to an individual in any given tax year.

[buildersmate]

OK, thanks Kempie. That makes more sense than anything I've been told over the phone. The reason why I though it worked in 'weeks' is because when they write to advise that one is short of enough NI contributions to count as a Qualifying Year, they quote in weeks (at the LEL rate) the voluntary contribution to be paid.
Two more supplementary questions then: -
Are 'credits' (for example, weeks whilst on JSA) assessed at a weekly NI contribution equivalent to the weekly LEL?
For those claiming Qualifying Years (for Basic State Pension calculation purposes) credit, through for example being in receipt of Child Allowance, does only being in receipt of 'whole and complete tax years' count as being credited (when calculating if a year is a Qualifying Year or not).