ITU‐T's Technical Reports and Specifications 907 City carbon footprint Annual amount of CO2 emissions in metric tons divided by the city population. Supplemental national reports on data and policies on greenhouse gas emissions were used when city‐level data were not available. Classroom size Number of students enrolled in public primary education programs divided by the number of classes in these programs. Primary education programs usually begin at ages five to seven and last four to six years. Primary education is counted as the equivalent of kindergarten through grade 5 in the US education system wherever possible. Commute time Assessment of the average commute time for workers commuting into or within a city across all modes of transport, measured in minutes. Cost of business occupancy Annual gross rent divided by square feet of Class A office space. Gross rent includes lease rates, property taxes, and maintenance and management costs. Cost of living Measure of the comparative cost of more than 200 items in each city. Counted items include housing, transport, food, clothing, household goods and entertainment. Cost of public transport Cost of the longest mass transit rail trip within a city's boundaries. The cost of a bus trip is used in the cities where there are no rail systems. Crime Amount of reported crimes in a city such as petty and property crimes, violent crimes and street crimes. Cultural vibrancy Weighted combination of city rankings based on: the quality and variety of restaurants, theatrical and musical performances, and cinemas within each city; which cities recently have defined the \"zeitgeist,\" or the spirit of the times; and the number of museums with online presence within each city. The \"zeitgeist\" rankings take into account cultural, social and economic considerations. Digital economy score Assessment of the quality of a country's information and communication technology (ICT) infrastructure and the ability of its consumers, businesses and governments to use ICT to their benefit. Domestic market capitalization Total number of issued shares of domestic companies listed at a city's stock exchange(s) multiplied by their respective prices at a given time. This figure reflects the comprehensive value of the market at that time in millions of USD. Ease of entry: number of countries with visa waiver Number of nationalities able to enter the country for a tourist or business visit without a visa. Excludes those nationalities for whom only those with biometric, diplomatic or official passports may enter without a visa. Ease of firing Ranking based on notification and approval requirements for termination of a redundant worker or a group of redundant workers, obligation to reassign or retrain, and priority rules for redundancy and re‐employment. Ease of hiring Ranking based on restrictions and regulations that employers must follow when taking on new staff. Ease of starting a business Assessment of the bureaucratic and legal hurdles an entrepreneur must overcome to incorporate and register a new firm. Accounts for the number of procedures required to register a firm; the amount of time in days required to register a firm; the cost (as a percentage of per capita income) of official fees and fees for legally mandated legal or professional services; and the minimum amount of capital (as a percentage of per capita income) that an entrepreneur must deposit in a bank or with a notary before registration and up to three months following incorporation.