Originally Posted by
sbm12
Sure. Every publicly traded US-based airline publishes data publishes ASM and RSM data in each quarterly and annual report.
I guess I should've made clear: "by US residents/citizens" since that is what the OP is after. I don't think that level of granularity is reported. Even if US airLines did report that we'd be missing travel by Americans on foreign and/or private operators.
GUWonder's point about US gov data might have some of it. But even that would be incomplete for OP's query as it wouldn't include travel by Americans where the USG doesn't have insight.