"+34%" / "−12%" / "—" delta string for a current-vs-previous count pair. Returns "—" when the previous period is zero (no baseline) so the UI doesn't shout "∞%" at the user the first time they open Insights with a week of data.
"—"
"+34%" / "−12%" / "—" delta string for a current-vs-previous count pair. Returns
"—"when the previous period is zero (no baseline) so the UI doesn't shout "∞%" at the user the first time they open Insights with a week of data.