The G-20 consists of the following economies: Argentina, Australia, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Korea, Mexico, the Russian Federation, Saudi Arabia, South Africa, Turkey, the United Kingdom, the United States, and the European Union. The G-20 aggregate is calculated taking the fifteen individual country members of the G-20 (other than France, Germany, Italy and the United Kingdom) plus the European Union as an aggregate. On 11 July 2017, the Argentine Authorities started to publish a new national CPI (December 2016 = 100) covering the whole country. This officially reported CPI-series starts in December 2016, and has now been included in the G-20 aggregate, from January 2018 onwards. The inclusion of the Argentinian CPI in the G-20 aggregate entails a clear break in the series. In January 2018, the inclusion of the Argentinian annual national inflation of 24.8% impacts the G-20 aggregate inflation by about 0.25 percentage point. The G-20 CPI aggregate is estimated at 2.5% without inclusion of Argentinian CPI.
*https://www.boletinoficial.gob.ar/pdf/linkQR/QlFlS1dmVmpOWXMrdTVReEh2ZkU0dz09