I notice everyone (except Tulla) in the top five share holders...

I notice everyone (except Tulla) in the top five share holders has reduced shareholdings since the last annual report:

Ross Taylor was 3.6% now 2.9%
HVR was 3.05% now 2.6%
Global House was 3.6% now 1.9%
BLB was 3.9% now 1.8%

Is this reduction through share dilution or have they all sold down? Certainly none seemed to have bought any more shares (except Tulla). Maybe part of the reason we do not get to see the top 20 very often.