Looks like the ArenaNet sanctioned and community maintained Guild Wars 2 Wiki updated their maps section with the help of a Jeuxvideo.com video screenshot. The astute observer will notice that in the bottom right hand corner there appears to be a toggle to view up to three layers on the map.
And then a super helpful GW2 and Guru Member named Carralpha seems to have taken a map and broken it down by zones borders and levels with the aid of a source video (see below).
Here is Carralpha’s breakdown:
1-15: Zones adjacent to all major cities (there are 4 since Rata Sum and the Grove seem to share a zone for this)
15-25: Kessex Hills, west of Kessex Hills, west of Wayfarer Foothills and north of Plains of Ashford
25-35: Gendarran Fields 30-40: South of Blazeridge Steppes (this doesn’t seem right position-wise but that’s what I seem to see), Timberline Falls
35-45: Valley Headland
40-50: East of Timberline Falls, Blazeridge Steppes
50-60: NW of Blazeridge Steppes, south of Timberline Falls
55-65: Sparkfly Fen 60: Island SW of Lion’s Arch
60-70: The zone with the volcano SW of Ancient Dwarflands, Regrown Flame
70-75: NE Orr
70-80?: Northernmost Shiverpeaks zone (with the big lake)
75-80: NW Orr
80: W Orr
Source Video used for Area Level Information: