Altoona, Iowa
Demographics
Table:
Historical population

Census	Pop.	Note	%±

1880	400	—
1890	326	−18.5%
1900	328	0.6%
1910	438	33.5%
1920	502	14.6%
1930	514	2.4%
1940	640	24.5%
1950	763	19.2%
1960	1,458	91.1%
1970	2,883	97.7%
1980	5,764	99.9%
1990	7,242	25.6%
2000	10,345	42.8%
2010	14,541	40.6%
2016 (est.)	17,938	[3]	23.4%
Iowa Data Center

Studying the following table concerning 'Altoona, Iowa' in the 'Demographics' section, create one factual sentence about the highlighted cells, without adding extra data and return it as JSON: {"answer": "YOUR ANSWER"}.