Based on experience in Germany in response to a compliance directive, a significant quantity of SO2 and NOX control installations were performed within outage periods consisting of less than four weeks.
Germany has the shortest outage periods reported stemming from control installations. 
mnli hypothesis: Germany has the shortest outage periods reported stemming from control installations.  premise: Based on experience in Germany in response to a compliance directive, a significant quantity of SO2 and NOX control installations were performed within outage periods consisting of less than four weeks.