"The numbers of drug seizures based on the GND, are provided in Table 10.2 for the years 2006-2010. For all years, the majority of the drug seizures contained cannabis (herbs, plants or resin). This percentage of cannabis related seizures gradually increased from 67.9% (95%CI: 67.4% - 68.4%) in 2006 to 72.8% (95%CI: 72.4% - 73.2%) in 2009. This increasing trend stabilized in 2010 with 72.3% of the seizures being cannabis related (95%CI: 71.8% - 72.7%). This time trend is in line with the increasing number of cannabis related drug offences (see Chapter 9, Section 2.1).
"When looking at the types of the seized cannabis, different time trends were observed. While there has been a more or less steadily decrease in the percentage of cannabis resin seizures from 2006 (16.2%; 95%CI: 15.8% - 16.6%) until 2010 (13.3%; 95%CI: 13.0% - 13.6%), the percentages of herbal cannabis (2006: 51.5%; 95%CI: 51.0% - 52.0%; 2010: 56.4%; 95%CI: 55.9% - 56.9%) increased quiet steadily. The increase for cannabis plants (2006: 0.2%; 95%CI: 0.2% - 0.2%; 2010: 2.6%; 95%CI: 2.4% - 2.8%) is partly due to an increase in data quality of the GND (between 2006 and 2007) (Dommicent, personal communication), but is also related to the increasing number of cannabis plantations being discovered (see also Table 10.6). Another remarkable trend is the declining percentage of XTC-like substances in seizures. From 2006 to 2010, the percentage seizures containing XTC, decreased from 5.9% (95%CI: 5.7% - 6.1%) to 1.7% (95%CI: 1.6% - 1.8%). For heroin, cocaine, amphetamines and LSD, no clear time trends were observed."

Source

Deprez, Nathalie, et al., "2011 National Report (2010 data) to the EMCDDA by the Reitox National Focal Point" (Brussels, Belgium: OD Public Health and Surveillance, Scientific Institute of Public Health, October 2011), WIV-ISP/EPI REPORTS N° 002, p. 199.
http://www.emcdda.europa.eu/a…