Thedumbshepherd, it's based on districts (rural and urban) not cities, true , I give you that.
Although you can't be sure that Mek'ele is the second most populated city of Ethiopia. Take it with a grain of salt, since there are more censuses that put Dire Dawa and some Adama as second most populous city.
Based on a professional study from march 2015, the second largest city population wise is Adama.
Dire Dawa(population wise the 5th place).
Mekele is 6th place population wise.
Jigjiga 154183 , 9th place. 2015
I'm sure Burao currently has a larger population than Jigjiga, Burao in 2008 had a pop. of 151451.
Burao 2008
5th place definitely goes to either Burao or Baidoa and not Jigjiga
One can't take censuses on random sites serious.
What makes you think Jigjiga will really grow in the future? What's the city's significance? It's just a regional state capital of no significance. They are definitely wrong with the speculation on Dire Dawa though, they probably didn't take in account that it would be the future industrial zone of Ethiopia, it's bound to outgrow most other regional capitals by 2050.