Police Scotland released the figures today as it launches a campaign to reinforce the message that sex without consent is rape.
The “We Can Stop It Campaign” will target men aged between 18 and 35.
Assistant Chief Constable Gillian MacDonald said: “In 2018 in Scotland sadly there are men who think it is OK to have sex with someone who is sleeping or suffering from the effects of alcohol or drugs.
“We are receiving frequent reports with at least 20% of all rapes reported to Police Scotland committed in such a way.”
“Investigations carried out by Police Scotland shows that men aged between 18 -35 years are more likely to be responsible and we want to send a strong message to them that sex without consent is rape, and if the person is unable to give consent to sexual activity, for whatever reason, it is rape.”
The campaign will be spread through social media using the Twitter hashtag #GetConsent with advertising to be placed in washrooms within clubs, bars and pubs.
ACC MacDonald said the force was “acutely aware” that sexual crime in Scotland was under reported.
She added: The reasons for this can be complex, however the only person responsible for such offences is the perpetrator. “
Sandy Brindley, of Rape Crisis Scotland, added: “The law is clear - if you have sex with someone who is sleeping or so drunk they can’t consent, it’s rape.
“It is crucial that people are aware of this.”