Every year. The result came out will always be in the same direction every year. Children with lower standards in Thailand are always or even a study of the Organization of economic cooperation and development.
Every year, the results are often the same direction every year is Thailand's knowledge is always substandard. Even the Organization for Economic Cooperation and Development.
Every year, the result often is in the same direction every year, that is, the child Thailand knowledge is always lower than the standard. Or even the study of organization for economic cooperation and development.