I couldn't find much in regard to adult abduction stats-but I found the following:
Kidnapping: An Investigator's Guide to Profiling is based on a three-part analysis of 100 randomly selected kidnapping cases prosecuted in the United States that have survived Supreme Court appeal.
Table 4.1 Predatory Kidnappong-Adult Victim
Victimology & Offender Characteristics-
1. The victim and the offender were strangers to one another. 56%
2. The victim and the offender had a relationship prior to the abduction. 39%
3. The offender and the victim are of different genders. 94%
6. The victim was low risk, i.e. not likely to be immediately missed or reported missing. 11%
Abduction site- The choice of site is consistent with the choice of victim: Those who had no prior relationship to their victim chose sites where the victim was selected at random. Those who had a prior relationship with the victim tended to target their home or workplace.
1. The abduction occurred in a public space. 67%
2. The victim was abducted from a private location (such as home, school, workplace). 33%
Modus Operandi -
1. The abduction was pepertrated by more than one offender. 11%
2. The victim was chosen randomly or opportunistically. 61%
3. Physical force was used to abduct the victim. 56%
4. The victim was abducted following verbal threats of harm to himself or herself and/or/ others. 17%
5. The victim’s abduction was the result of persuasion or deception. 39%
6. The offender used a firearm to facilitate the abduction. 22%
7. The offender used a knife to facilitate the abduction. 17%
8. The offender used a weapon, other than a knife or a firearm, or did not use a weapon, to facilitate the abduction. 28%
9. The offender sexually assaulted the victim during the abduction. 94%
10. The offender physically assaulted the victim during the abduction in a manner that did result in death. 17%
11. The offender physically assaulted the victim during the abduction that did not result in death. 56%
12. The offender did not assault or physically harm the victim during the abduction (excludes sexual assault). 28%
13. The offender transported the victim during the abduction 78%
14. The offender did not transport the victim during the abduction. 22%
15. The offender exhibited obvious psychotic symptoms (delusions, hallucinations etc.). 0%
16. The offender held the victim captive for greater than 24 hours. 17%
17. The offender held the victim for less than 24 hours. 83%
18. The kidnapping occurred in the morning (midnight-8am). 28%
19. The kidnapping occurred during the day (8am-4pm). 6%
20. The kidnapping occurred in the evening (4pm-midnight). 66%