A/HRC/28/60 Figure III Estimates of corruption-based illicit financial flows, assets frozen and returned from OECD countries, 2006–June 2012 Source: Larissa Grey and others, Few and Far, 2014 (see footnote 14), p. 21. 17. According to data collected by StAR only four OECD countries managed to return stolen assets to countries of origin after completing national legal procedures during the 6.5 year period between 2006 and June 2012. They are Australia, Switzerland, United Kingdom and the United States of America, with Switzerland and the United States of America, each accounting for about 40 per cent of all asset returns to foreign jurisdictions.17 18. The results demonstrate the difficulties and barriers existing in the complex process of tracking stolen assets, freezing them, or returning them through criminal or nonconviction based confiscation, private civil action and domestic investigation. The political will to combat corruption and to recover assets in receiving States, timely and well documented requests for mutual legal assistance and close collaboration between investigating authorities in countries of origin and destination are all essential to ensure the successful repatriation of stolen assets. States continue to face challenges in recovering assets owing to differences between legal systems, the complexity of multijurisdictional investigations and prosecutions, the limited implementation of effective domestic tools such as non-conviction-based forfeiture for asset recovery, lack of familiarity with the mutual legal assistance procedures of other States and difficulties in identifying the flow of corruption proceeds. In addition there are particular challenges posed in recovering the proceeds of corruption in cases involving individuals occupying prominent public positions. 19. One significant way of reducing illicit gains and related illicit financial flows is to focus on the supply side, the bribe payers. An estimated US$ 1 trillion is paid in bribes worldwide each year, and bribery in the developing world may amount to an equivalent of 15–30 per cent of all ODA. Ending impunity on the supply side must be part of the efforts to reduce illicit financial flows. An OECD report taking stock of the total number of individuals and legal persons sanctioned or acquitted in relation to foreign bribery from 1992 to 2012 shows significant disparities between prosecutorial efforts and the enforcement of anti-bribery legislation in the 40 States parties to the OECD Convention on Combating Bribery of Foreign Public Officials in International Business Transactions (Anti-Bribery Convention).18 20. However, even if transborder bribery is prosecuted, monetary sanctions frequently do not reach the country where the bribe took place. An analysis by StAR of 395 foreign 17 18 8 Larissa Grey and others, Few and Far (see footnote 14), p. 20. OECD, “Illicit Financial Flows from Developing Countries, Measuring OECD responses”, (Paris, 1994), pp. 84–93 and Annual Report of the OECD Working Group on Bribery 2014, pp. 14–19.