Downtown Houston
------------------------------ 2020 ------ 2010 ------ 2000 ------ 1990 ------ Growth ------ Density
Downtown --------------------- 17,138 ----- 14,342 ----- 11,882 ------ 7,029 ---- 19.5% ---- 20.7% --- 69.0% ------- 4.5 km² --- 3,834.9 inh./km²
Midtown ------------------------ 10,820 ------ 7,441 ------ 4,710 ------ 2,761 ---- 45.4% ---- 58.0% --- 70.6% ------- 2.8 km² --- 3,861.5 inh./km²
Houston MSA --------------- 7,122,240 -- 5,920,416 -- 4,693,161 -- 3,750,883 ---- 20.3% ---- 26.1% --- 25.1% -- 21,416 km²
Downtown Houston is the freeway loop and the 3 census tracts match perfectly with the definition.
Each one of them tells a completely different story: one is the norwestern corner, where all the tall buildings are; the other embraced the first, in an L shape, where all the parking lots are; and the third is the bit northern of the river. Apparently they've built an university campus there and population went from zero in 1990 to 8,200 now, but it actually decreased this decade, making Downtown numbers not looking that spectacular. In fact, it's actually lower than the Houston MSA, making one of the very few in the list to grow slower than its metro area.
About Midtown, located immediately south of Downtown, it's the typical central neighbourhood that's taking advantage from Downtown's boom. I brought its numbers just to register.