Together they received 58% of total OOF during the period 2006-15. Together, the top ten donors (bilateral and multilateral) provide over 81% of total aid for trade (Figure 11.11). For trade-related OOF, the concentration is even stronger, with the top ten donors providing over 97.2% of the funds (Figure 11.12). It enables the movement of people, goods and services and provides access to local, regional and global markets as well as health, education, water, energy and communications services. Infrastructure is estimated to have a socioeconomic rate of return of around 20%.