When you see in the torrent client an availability of 2.000, it means the other peers to whom it is connected share together one full copy in addition to your own full copy. However it doesn't mean that any of them got a full copy (then they would be a seeder and your client won't connect to it). Then if you quit and one of them drops off, no complete copy will be shared. therefore, if there then aren't shown multiple seeder (or seeds) in the client, you should continue to seed.
Our rules require 3 other seeds, i.e. 4 with you all together, before you can stop seeding. This is to ensure the torrent will survive once the uploader left seeding and one or the other member who has completed the download quits seeding early.
You can check on the number of seeds both in your client, that would be "0 (4)" seeds in µTorrent for you and 3 others, or on the site. Both ways are fine.