Solution: www.nwa.com
View your SkyMiles statement there formatted a lot more clearly and easier to read, better sortable (thought not exactly how you want it), etc. (If only DL would keep the nwa.com far superior web site, including things done there far better such as a clear and readable mileage stating showing actual flight #s, flight dates & posting dates, fare class paid & flown, etc. -- all of which delta.com, of course, lacks.)

What you can do is copy and paste the nwa.com output into Excel and then sort it how you'd like to, however.