This means Lebanon is among the least peaceful countries in the world. You can download the full report and check out other countries [Here].
Here are few rankings related to Arab countries (Out of 162):
Saudi Arabia: 97
The 2013 Global Peace Index (GPI) shows that the world has become less peaceful, with a sharp rise in the number of homicides. The GPI measures peace in 162 countries according to 22 qualitative and quantitative indicators of the absence of violence and fear of violence. This is the 7th annual edition of the index.
And here are screenshots showing Lebanon’s rankings from 2010 till 2012.