Background: Some countries were not included for various reasons, primarily the lack of necessary data. The following United Nations Member States were not included in the 2014 report: North Korea, Marshall Islands, Monaco, Nauru, San Marino, Somalia, India, Pakistan, South Sudan, and Tuvalu.
Question: What is the main reason that countries were excluded from the 2014 report?
Answer:<extra_id_0>.
<extra_id_0> lack of necessary data<extra_id_1>