'Amongst other factors' is a way to introduce or highlight one factor that influences something. It also obviously suggests that there are several factors that are relevant. A factor here is something that influences something else, or a situation. 'Amongst other factors, the lack of experience of the climbers led to them getting lost'. 'Amongst other factors, racism appears to be a dominant concern for new immigrants'.

There are many factors (reasons) for the fall in imports and exports. One factor is the decline in global trade. This factor is somewhere in ("among/amongst") the whole group of factors. There is a mistake in the sentence. "is experiencing" or "has experienced" are possible. "experience" is wrong.

All the three comments I made above were the answers from another native American teacher.Thanks for his help. And I also express my gratitude to the two good Samaritans following.

amongst other factors just means "together with some other things"

it is usually used with some negative sentences to explain something