Marusa, I clicked through your survey without answering the questions, to see what it is about, and you are asking for some very sensitive information about things like drug use and prostitution. Are you doing this as a university project? I think, at the very least, you need to add a front page explaining who you are and giving contact details, explaining that some sensitive questions will be asked, making a statement about anonymity and confidentiality and giving people the chance to click to say they consent to the survey. Perhaps your supervisor could help you to add a page like this. Also, it is not clear if you are asking about the economy in Slovenia - if this is the case then you need to say that you want people in Slovenia to respond.