Transparency International's annual Corruption Perceptions Index ranks 180 countries on the transparency of their dealings in the eyes of experts and business people.
The survey measures perceptions of the use of public office for private gain, nepotism, bribery, anti-corruption systems, the diversion of public money and state capture - which is when private interests influence a state's decision-making processes to their own advantage.
It uses a scale of zero to 100, where zero is highly corrupt and 100 is very clean.
This year, Australia maintained its score of 77 from 2017 to stay at 13th.
Transparency International Australia’s chief executive, Serena Lilly white, says Australia's ranking over the last seven years has slipped by eight points.
Listen to the feature in Bangla in the audio player above.
