I have been downloading the blockchain to a new client and it has been at it now for almost a week. One thing I notice is that as it is getting close to the end, it is slowing down a lot.
For example, it just downloaded 93 blocks in 488 seconds or 1 block per 5.25 seconds. If the entire block chain had downloaded at this speed then it would take: 418950 x 5.25 = 2,199,488 seconds or 25 days. Since, it has taken less than a week to do it, the older blocks must have downloaded faster.
What is the explanation for this?