The Gridded Population of the World, Version 4 (GPWv4): Population Density, Revision 11 consists of estimates of human population density (number of persons per square kilometer) based on counts consistent with national censuses and population registers, for the years 2000, 2005, 2010, 2015, and 2020. A proportional allocation gridding algorithm, utilizing approximately 13.5 million national and sub-national administrative units, was used to assign population counts to 30 arc-second grid cells.
The purpose of used lubricants and oil audit was to execute assessments on activities and services of organizations under sectors responsible in generating used lubricants and oil or its wastes in any regard. Used lubricants and oil (ULO) audit/ survey and inventory was executed under the requirements expected from the environmental audit protocol.