I would like to estimate the total number of hashes (double SHA-256) that have been performed for bitcoin purposes.
As an estimate, I downloaded mining stats, massaged the numbers (assuming the rate shown is for the period ending at the date indicated and starting at the date before), came to 201⋅1024 hashes (equivalently 287.38 or 288.38 SHA-256) on Oct 28, 2017.
[update: 517⋅1024 hashes that is 288.74 or 289.74 SHA-256 by May 4, 2018].
Did I goof badly in that estimation of the hashes used for mining?
What other comparably non-negligible number of hashes is performed for bitcoin purposes, and how can that be estimated?
Clarifying: I'm looking only for things that represent a sizable fraction of the number of hashes spent for mining, say at least 0.5%; I'm totally willing to ignore the rest.