I always thought it would be great, IF, a Full date for the Street entries was give, rather than just the year. Ie, I know a Rachel Graham was born 19 April 1877 at 19 Cullingtree Place Belfast, ( 1877 street directory shows a Francis Garvey, as occupant), Mary Graham was born 14 Sept 1886 at 9 Gibson Street Belfast, as was her sister Annie on 27 March 1888. But the Graham name does not appear at # 9 until the 1890 entry. (1880 entry for # 9 is Vacant).