[benchmark] Bug Fix for data size.
[benchmark] Bug Fix for data size.

openconnectome/open-connectome,openconnectome/open-connectome,neurodata/ndstore,neurodata/ndstore,openconnectome/open-connectome,neurodata/ndstore,neurodata/ndstore,openconnectome/open-connectome,openconnectome/open-connectome,openconnectome/open-connectome