per cent developed的意思 .求高手帮忙翻译一句话

per cent developed的意思 .求高手帮忙翻译一句话
probably a large fraction oniy of the per cent developed in increase of national product.这句话是什么意思?
不要用翻译软件的答案，翻译软件我也会用，我就是判断不出来这句话的结构，翻译不出来。请英文高手帮忙一下，谢谢哦。谢谢后来的两位朋友，段落是It is doubtful if United States
exports will have any great growth in these future years; probably a large
fraction oniy of the per cent developed in increase of national product.
However, those countries in Trade Agreement areas will show remarkable
results especially in the indmtrial products with regional comparative advantage.这是一篇外贸研究的专业文献。谢谢各位