Save mean and stddev of the gmvs per each site
Save mean and stddev of the gmvs per each site


Former-commit-id: 6a850e031cf88e153b6572ab5b8ab98bce175989 [formerly fc59b690974e93b9f026960a1421f2839cab2e21]
Former-commit-id: 4d8798348d5f31d60688133eae7a1c03819f03f3
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine