The Logistics Performance Index reflects perceptions of a countrys logistics performance based on the efficiency of the customs clearance process, quality of trade- and transport-related infrastructure, ease of arranging competitively priced international shipments, quality of logistics services, ability to track and trace consignments, and frequency with which shipments reach the consignee within the scheduled time. The index ranges from 1 to 5, with a higher score representing better performance. Percent of highest performer refers to the percentage of the score of a country in comparison to the score of the highest performing country that year. Data are from the Logistics Performance Index surveys conducted by the World Bank in partnership with academic and international institutions and private companies and individuals engaged in international logistics. The 2018 round of surveys covered close to 6,000 country assessments by around 1,000 international freight forwarders. Respondents evaluate eight economies on six core dimensions on a scale from 1 (worst) to 5 (best). The economies are chosen based on the most important export and import markets of the respondents country, random selection, and, for landlocked countries, neighboring countries that connect them with international markets. Scores for the six areas are averaged across all respondents and aggregated to a single score using principal components analysis. Details of the survey methodology and index construction methodology are available in Arvis, Ojala, Wiederer, Shepherd, Raj, Dairabayeva, Kiiski: "Connecting to Compete 2018: The Logistics Performance Index and Its Indicators", see Appendix 5 for methodology.