“Natural gas imports from Canada has steadily declined in the past four years.”
should be
“Natural gas imports from Canada have steadily declined in the past four years.”
Feels more natural to use “import” as only one kind of import is being discussed.
Added to my list.
@Alexan, done ([en] Improve NNS_IN_NNP_VBZ · languagetool-org/languagetool@c9983c7 · GitHub).
The rule will be available tomorrow in the snapshot (Index of /snapshots/) and on languagetool.org.