Well I believe my work experience was the reason The average is 14 years and I am around 8 in the private sector with heavy part time ngo exp since 6 years. + maybe under grad GPA around 3.0. Grad school gpa: 4.0, gre V164 Q162 awa 4.5.
I imagine they have tons of applications and maybe are looking into Public service experience. It would have nice to go but not mandatory to get great Public admin teachings, other good programs out there. Good luck for the rest