For the first time
The 2012 index, released earlier this month, was done on 158 countries and the 2007 index on 120 countries, according to Vision of Humanity's website.
The index showed that the world had become more peaceful for the first time since 2009. All regions excluding the Middle East and North Africa saw improvements in levels of overall peacefulness.
The 2012 GPI was the sixth edition of the world's leading measure of global peacefulness.
Produced by the Institute for Economics and Peace, the GPI ranks 158 nations using 23 qualitative and quantitative indicators which gauge ongoing domestic and international conflict, safety and security in society and marginalisation.
It showed Iceland was the most peaceful country for the second successive year, Syria dropped by the largest margin, over 30 places, to 147th position.
Somalia remained the world's least peaceful nation for the second year running.
Least peaceful
The end of a civil war saw Sri Lanka rising 30 places to 103.
For the first time, sub-Saharan Africa was not the least peaceful region and has steadily increased levels of peacefulness since 2007.
The Middle East and North Africa was now the least peaceful region, reflecting the upheaval and instability caused by the Arab Spring.
And for the sixth consecutive year, Western Europe remained markedly the most peaceful region with the majority of its countries in the top 20.
The Asia Pacific regions' overall score improved by the largest extent from last year and included three of the top five risers.
North America experienced a slight improvement, continuing a trend since 2007, with the US raking at number 88.
Latin America experienced overall gain with 16 of the 23 countries seeing improvements to their GPI score. – Sapa