URGENT!!!! Definitely will up vote

In a study to identify the difference of the ratio of total loans outstanding to total assets among banks in Germany and Great Britain, a sample of 145 banks was selected from each country. As for the sampling, the pairings were made in such a way that the two members were as similar as possible in regard to such factors as size and age. Given that the data distribution is unknown.

Determine the most appropriate statistical technique for above test. State the reasons of your choice.