The total number of all B2B publication is estimated between 9.000 – 10.000 titles.
Unfortunately we can present a long term development trend only on trade magazines which have been audited. Please keep in mind that the increase in circulation relates to an increasing number of audited publication, the decrease in circulation does not.
Please keep in mind that the German reunification process does change the base in 1990/1991.

Source: IVW Annual Report 2004/2005
See a short overview on the 2004 Press Statistic
Or download a more detailed version as PDF