the cost of Operation Zeus, are unknown. While, in terms of content, the measures appear much targeted, the lack of available figures on those who were not apprehended and end-result of apprehensions (e.g. release, asylum application, expulsion, voluntary return etc) hinder any effort to assess the cost-effectiveness of the measures. Table 10. Statistics Operation Zeus, 2.8.2013-31.12.2013 Period Migrants Checked Migrants arrested 02.8.2012 – 31.12.2012 65,766 4,145 01.1.2013-31.1.2013 9,167 275 01.2.2013- 31.12.2013 N/A 1,126 TOTAL N/A 5,546 Source: www.astynomia.gr Specifically for Operation Xenios Zeus, the direct output made available by the Hellenic Policy is the number of migrants stopped and those who were, in the end, apprehended. Figure 6: Checks and Apprehensions – Operation Xenios Zeus, Aug.- Dec. 2012 In quantitative terms, the sweeping nature of the operation produced an impressive number of stops-and-checks. In qualitative terms, however, more than 90% of the migrants that were rounded up were subsequently released. In other words, the chances that a rounded-up person would be an irregular migrant were as low as 6%. Suffice to note that in the course of 2013, the arrest rate dropped even lower. Taking into account the thousands of police officers initially deployed and the hours spent to operate these round ups and subsequent controls, the operation does not appear to be a cost- Page 36