(Thomson Reuters Foundation) – More and better data is needed to track progress in the global drive to eradicate modern slavery and human trafficking as many victims – including people trafficked for their organs and child soldiers – are going uncounted, leading anti-slavery groups say. About 40 million people were trapped as slaves last year – mostly women and girls – in forced labour and forced marriages, according to the first joint effort by key rights groups to count the number of victims worldwide, published last month.