In a direct communication, the source explained:

In the case of tables of population, vital statistics and migration in 2015 and 2016 will be published balance only for the first half and year. There will not be disseminated quarterly tables about the population (I, II, III, I-III and IV quarter). The reason for the lack of quarterly tables are delays in the transfer of data from Registration Civil Office to the statistics, and consequently the lack for each quarter of full information on the number of facts of vital statistics and migration. These delay are caused by the implementation (since March 2015), a new system of the Ministry of Interior for the registration of civil status acts (computer system Zródlo).

In response, we have not marked the series as "discontinued," but they will remain frozen with their current values until the source resumes production. The quarterly series run from 2005Q1 to 2014Q4. Geo coverage includes the nation and NUTS 1, 2 and 3 areas, but not all concept-geo pairs exist.

The series reside in the historical catalog (Poland » Demographics » Components of Change | Population » Quarterly) and include, for example:

• VSQLBTHUQ.IPOL_LO = Components of Change - Live Births, (#, NSA) - for NUTS 2 Lódzkie
• VSQDTHUQ.IPOL     = Components of Change - Total Deaths, (#, NSA)
• VSQPOPUQ.IPOL_CIE = Population - Total, (Ths. #) - for NUTS 3 Ciechanowsko-Plocki

Because catalog locations are subject to change, the upper-right search box on DataBuffet.com provides a "find in catalog" mode that accepts a mnemonic.