Bulgaria ranks tenth among the 19 countries classified as potential leaders under the technology achievement index (TAI), data from UNDP's Human Development Report 2001, show. Bulgaria precedes Poland, Croatia and Romania and is behind Greece. Bulgaria's overall TAI rank is 28th among 38 countries. According to the report, which encompasses 72 countries, Finland tops the TAI rankings, followed by the US, Sweden and Japan. At the third regional forum on information society development, where the report was presented, experts expressed the opinion that e-signature law is not the only prerequisite for the development of e-commerce. By late 2002, Internet users in Bulgaria had tripled in comparison with a study conducted two years ago. According to Vitosha Research polling agency, 12.2% of Bulgarians of age surf the net; some 50% of all Internet users are aged 18-30 and 1/4 are aged 31-40; while pensioners are not using the Internet at all.