There was a rare annual increase of nearly one percentage point in the global average number of women members of parliament (MPs) in 2012, Inter-Parliamentary Union (IPU) said in a statement released here ahead of international women's day.
The statement credited reservations for the marginal increase.
It said the increase "underlined once again that quotas remain pivotal to efforts redressing the gender deficit in politics".
Releasing its annual analysis on the statistics on women MPs, IPU said 2012 represented a year of higher than usual level of progress on women's political participation.
"The global average of women in parliaments by the end of 2012 stood at 20.3%, up from 19.5% in 2011. With the exception of 2007, the average annual rate of increase in recent years has been 0.5% point," the statement said.
The use of either legislated or voluntary quotas, in some of the 48 countries where elections were held in 2012, were largely responsible for the above-average increase of women MPs.
Nine out of the top 10 countries which witnessed the highest growth in the number of women MPs in their lower house of parliament had used quotas.
"Although quotas remain contentious in some parts of the world, they remain key to progress on a fundamental component of democracy - gender parity in political representation," said Anders B. Johnsson, IPU secretary general.
Highest electoral gains for women MPs were witnessed in Senegal, Algeria and Timor Leste, with all three countries using legislated quotas for the first time.
With 31.6% women MPs, Algeria is now the first and only Arab country to have more than 30% women holding parliamentary seats.
It was the highlight in a region which failed to deliver on the promise of democratic change in the Arab Spring countries of Egypt and Libya and which continues to have the lowest regional average of 13.2%.