Results of time-series analysis of measurements of total ozone content (TOC) using the TOMS spectrometer for the period fall 1978 to spring 1993 are presented. TOC trend levels were ascertained for four stations in middle and high latitudes of European Russia and Norway. Emphasis is on identification of decadal and seasonal trends within on overall decline in ozone content in middle and high latitudes of both hemispheres. Trends computed using an earlier version of processing of TOMS data (version 6) are compared with data processed using the latest version 7, and differences are noted, especially during the autumn-winter period.