The study of more than 1100 US and international IT security professionals also found that the remaining data losses were accidental in nature.
According to Imperva, the IT security vendor that sponsored the survey, the most effective data security strategy noted by respondents was one that sues technology to protect applications and databases, in parallel with a more traditional approach.
For example, says Imperva, web application firewalls were among the top five rated technologies for reducing the number of data loss incidents.
Other technologies used included network data loss prevention, full drive encryption, server/endpoint hardening, and endpoint data loss prevention.
One interesting conclusion from the report, which is downloadable from Imperva's website, is that almost two-thirds of organisations either didn't know if they suffered any data loss incidents, or said that they were not aware that they experience any events.
However, of the respondents that did realised they had been the victim of a data loss or breach, 46% said they had seen a decline in incident numbers, whilst 27% said they had seen the same number in the previous year.
Amichai Shulman, the firm's chief technology officer, said that data security is an emerging practice requiring practitioners to navigate numerous mandates, threats and technologies.
"This survey will help security teams identify what their peers find successful and hopefully help make improvements to their own strategy and operations", he said.