First 1.6 million BTC were mined at a difficulty of 1, which requires about 7Mhash/s.
At first, the code was not nearly as optimized as it is now.
This means there were no more than 5-10 people mining (perhaps less) for the first 32,000 blocks.
I don't have the exact proof, but I highly doubt this.
These people used CPU mining which uses less electricity.
Cpu mining may use less electricity, but it's efficiency is TERRIBLE. As in... My 5870 gets 400mh/s for the (way highside)300 watts it uses. That's 1.33h/w.
My core 2 quad at overclocked to 3.2 must be using something around ~100watts and it gets about 12mh/s. That's 0.12mh/s.
It's not about how much you use, but about the efficiency.
My numbers are somewhat fuzzy, too lazy to look up hard data, but you get my point.