A high of $31.90 was reached on 2011-6-8
Five months later a low of $1.99 was reached on 2011-11-17
The reduction in price was $29.91 per Bitcoin (~93.8%)
If we apply a similar percentage correction (~93.8%) to the high of $266 that was reached on 2012-4-10.
That will result in a reduction of $249.41 per Bitcoin down to a price of $16.59.
There are, however, several fundamental differences which can result in a higher % variance:
1) There are currently more Bitcoins in circulation than in 2011
2) There are more adopters/users/companies that accept BTC
3) There are significantly more speculators/hoarders who are playing BTC like a stock market
4) Today's considerably more mainstream media attention can exaggerate or understate events
