1977The Ecosystems Center 1977No. of attendees: 801978The Ecosystems Center 1978No. of attendees: 1481979The Ecosystems Center 1979No. of attendees: 2361980The Ecosystems Center 1980No. of attendees: 2281981The Ecosystems Center 1981No. of attendees: 2401982The Ecosystems Center 1982No. of attendees: 2161983The Ecosystems Center 1983No. of attendees: 164
