1896-1914: Years Run From Feb.1 To Jan. 31. 1915: Feb. 1 - Dec. 31 (11 Months). 1916-44: Calendar Years. About 36 Districts Were Annexed By The City Of Pittsburgh In 1894-1931. The Only Important Area Was The City Of Allegheny, Annexed Dec. 1907, With Assessed Value Of $109.4 Million In 1909 Compared To That Of Former Area, $587.3 Million In 1910. Source: Superintendent, Pittsburgh, Bur. Of Build. Insp., Dept. Of Public Safety (By Correspondence).
This NBER data series a02052 appears on the NBER website in Chapter 2 at http://www.nber.org/databases/macrohistory/contents/chapter02.html.
NBER Indicator: a02052
Release: NBER Macrohistory Database
National Bureau of Economic Research, Value of Permits For New Buildings for Pittsburgh, PA [A02052US38300A398NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/A02052US38300A398NNBR/, July 5, 2015.