Last week in the legal notices of "the Guide" 45 people filed for a license to carry a concealed deadly weapon in Sussex County. Those are just the listings in the Guide hard to say how many more actually filed.
The filing process http://courts.delaware.gov/forms/download.aspx?ID=33278 and here
Looks like it would cost about $300 before you are done with the publishing fees, concealed weapon course and application fee.
I was not able to find an on-line list of people in Delaware who have a concealed gun permit, maybe it is some where out there. I would guess in 2015 about 2,000 in Sussex County applied for a license. In 2013 The Prothonotary says 2,617 people are currently holding active permits to carry a concealed firearm in Sussex County. http://www.wboc.com/story/22809727/concealed-gun-permits-up-in-sussex-county In all of 2012, only 435 applications were filed. I think we can call this the Obama effect.
and the Delaware license is allowed in these states - none of which are adjoining Delaware
and those states tend to vary as to if they will or will not recognize the Delaware License.