Please note that #nerdminers is not ASIC mining, so its mining efficiency is very low. Thus its percentage of the global Hashrate would be unnoticeable, and I guess no block would have been mined on any of them.

Even if Nerdminer's efficiency (W/THs) were equivalent of ASIC, think of it in energy terms:

Each netminder consumes 1W per year.

Now think in the thousands and thousands of ASIC miners consuming 2 or 4 KWh!!

Nothing remotely close.