No, it's been #1 on a few occasions. Most people look at the default settings though (6 months ranking) and we're constantly going up on this.. Although this doesn't necessarily reflect the size of our user-base (Debian for instance has way many users than us, it wouldn't even be fair to compare us to them in that respect) it shows that our project is catching attention and it does attract a lot of newcomers to Linux Mint, at least it makes people try our liveCDs.
We can't rely on the number of downloads to know the size of our user-base either because most mirrors don't keep stats and because some external sources (distrowatch for instance) link directly to some of our ISOs.
We can only compare in a relative way to other distributions via tools such as web stats. Look here for instance:
http://distrowatch.com/awstats/awstats. ... etail.html . We're number 6 here as well and this is more meaningful than anything else.. although slackware and a few others don't modify their user-agents, we only modify Firefox's user-agent and some of the distributions above us link to distrowatch from community/official websites (we don't). Overall I believe this is the only meaningful source of comparison between us and other distributions.. but again, it doesn't tell us how many users run Mint...
I guess we'll never really know

Clem