The volume index of industrial output describes the relative change in the volume of industrial output at fixed prices when compared with a specific base period. The volume index of industrial output is based on an inquiry sent to enterprises or establishments. Enterprises and establishments are asked about volume or value data every month.
Official Statistics of Finland (OSF):
Volume index of industrial output [e-publication].
ISSN=1798-9272. Helsinki: Statistics Finland [referred: 2.4.2015].
Access method: http://tilastokeskus.fi/til/ttvi/meta_en.html