http://www.pollyklaas.org/about/national-child-kidnapping.html

National Child Kidnapping Facts
99.8% of the children who go missing do come home.
Nearly 90% of missing children have simply misunderstood directions or miscommunicated their plans, are lost, or have run away.
9% are kidnapped by a family member in a custody dispute.
3% are abducted by non-family members, usually during the commission of a crime such as robbery or sexual assault. The kidnapper is often someone the child knows.
Only about 100 children (a fraction of 1%) are kidnapped each year in the stereotypical stranger abductions you hear about in the news.
About half of these 100 children come home.