It develops tools for fighting corruption and works with other civil society organizations, companies and governments to implement them. Since 1995, Transparency International has issued an annual Corruption Perceptions Index (CPI); it also publishes a Global Corruption Report, a Global Corruption Barometer, and a Bribe Payers Index. In 2010, Transparency International developed a five-year strategy with six strategic priorities organized by the following categories: People, Institutions, Laws, Values, Network, Impact. In 2015, Transparency International (TI) developed a five-year strategy which sets out their collective ambition for the coming years. Together against Corruption: Transparency International Strategy 2020 is a strategy by and for the Transparency International movement. This strategy is based on more than 1500 external and internal contributions addressing both the corruption environment of today and the one TI anticipates in the years ahead. The Corruption Perceptions Index (CPI) ranks countries and territories based on how corrupt their public sector is perceived to be. It is a composite index – a combination of polls – drawing on corruption-related data collected by a variety of reputable institutions. The CPI reflects the views of observers from around the world. The Corruption Perceptions Index has received criticism over the years. The main one stems from the difficulty in measuring corruption, which by definition happens behind the scenes. The Corruption Perceptions Index therefore needs to rely on third-party survey which have been criticized as potentially unreliable. Data can vary widely depending on the public perception of a country, the completeness of the surveys and the methodology used. The second issue is that data cannot be compared from year to year because Transparency International uses different methodologies and samples every year. This makes it difficult to evaluate the result of new policies. The Corruption Perceptions Index authors replied to these criticisms by reminding that the Corruption Perceptions Index is meant to measure "perception" and not "reality". They argue that "perceptions matter in their own right, since... firms and individuals take actions based on perceptions". Transparency International consists of chapters – locally established, independent organizations – that address corruption in their respective countries. From small bribes to large-scale looting, corruption differs from country to country. As chapters are staffed with local experts they are ideally placed to determine the priorities and approaches best suited to tackling corruption in their countries. This work ranges from visiting rural communities to provide free legal support to advising their government on policy reform. Corruption does not stop at national borders. The chapters play a crucial role in shaping its collective work and realising its regional and global goals, such as Strategy 2015.