Progress percentage between two time periods

I use Grafana with influxdb to measure user accounts creations. I have a SingleStat panel that show the number of user accounts creations over a period of time (eg. last 7 days).

SELECT count(value) FROM "account_creations" WHERE $timeFilter

Is it possible in another SingleStat panel, to display the progress percentage between selected period of time (eg. D-7 to today) and the previous period (eg. D-14 to D-7). As an example, if there were 50 account creations during week 1 and 100 during week 2, the panel should show +100%.

I tried hard coding two metrics requests without using $timeFilter:

SELECT count(value) FROM "account_creations" WHERE time >= now() - 7d


SELECT count(value) FROM "account_creations" WHERE time >= now() - 14d AND time <= now() - 7d

but even then, I couldn’t find how to do math on those metrics requests results.