For context, my understanding is that SpaceX builds one new Falcon 9 upper stage (not reused) every day. I doubt there is another entity on earth building a new

For context, my understanding is that SpaceX builds one new Falcon 9 upper stage (not reused) every day. I doubt there is another entity on earth building a new rocket every month. SpaceX has a large fleet of Falcon 9 reusable boosters, but still needs to build one every now and then.