Most tigers are kept in captivity. Now, it's most likely that there are more in captivity than in the wild.
Humans are always improving their settlements, which cuts into tiger territory. The more human population grows, the more humans need homes, which will, agian, cut into tiger territory, forcing them into smaller and smaller spaces. From there, tigers might breed over and over again, in the same group. This weakens the gene pool, causing the cubs to become not as healthy and strong as their parents and grandparents.
So please, help these amazing animals. Sure, this might sound cheesy, but I love tigers very much, and it would devistate me, and many others to hear that they went instinct. Thank you :)