Just finished Duolingo tree
It only took 13 months for me to finish the tree along the way I went back an did many of the classes over. I finished with 47% fluency but I guess that assumes that I know every word and can use in a sentence. Any starting at 65 has been quite a challenge for me I think will do is over. Bottom line thank you Duo lingo for creating this wonderfully useful tool.
Well done; completing a course is something I haven't done yet, and it takes a lot of effort, work, concentration, and a good memory! Also, I wouldn't give the fluency measurement much attention; it wouldn't be possible for it to calculate how proficient you are (this is because you might use other resources outside of Duolingo, which is something the measurement wouldn't acknowledge). It's actually based on the accuracy of our answers and your progress in the course (it usually maxes out between 50% and 60% fluent at some point). Good luck; further learning with other resources might be effective since Duolingo wasn't intended to get you to proficiency (but an intermediate level).