The suicide rate of Foxconn has always been significantly lower than the US. Part of the reason is because healthy, working adults aren't likely to commit suicide in the first place. Even so, in 2010, which was by far the worst year, 14 Foxconn employees committed suicide out of 930,000 employees [1]. The US suicide rate is 13.7 out of 100,000 [2].
It's worth noting that there are qualitative differences to be considered, and people committing suicide at that rate (or any rate at all) should be investigated to address the conditions of these workers. To simply look at a comparison of the rates misses out that different factors and motivations drive these suicides.
Suicide rates are also very biased by how employers, friends and family, and authorities handle the death.
Across many cultures people tend to underreport suicides - but to different extents.
It's also worth noticing that some behaviors leading to death like overdose, heavy drinking and dangerous activities are not counted as suicide but sometimes they share the same psychological conditions.
[1] https://en.wikipedia.org/wiki/Foxconn_suicides
[2] https://en.wikipedia.org/wiki/List_of_countries_by_suicide_r...