City, Missouri, in 1964. From 1964 to 1966, Kenworth nearly doubled its yearly truck sales. In 1968, the company established Kenworth Australia; in place of importation and conversion, right-hand drive trucks were produced and developed in Melbourne, Australia. In 1969 Kenworth hired Gary Ridgway who worked in their paint department for the next 32 years during which time he murdered 48 women as the "Green River Killer" 1970s: Product line diversification During the 1970s, the company underwent further expansion, adding an all-new facility in Chillicothe, Ohio, in 1974. The W900 and K100 underwent their most substantial revisions, becoming the W900A and K100C. Kenworth added two new product lines in 1972, adding the C500 6x6 severe-service conventional and the Hustler low-cab COE (developed jointly with Peterbilt and produced in Canada). The same year, parent company Pacific Car and Foundry adopted its current name PACCAR. Coinciding with the 50th anniversary of the company, annual Kenworth sales exceeded 10,000 for the first time for 1973. For 1976, Kenworth launched a flagship customization series, the VIT (Very Important Trucker) with a high level of interior features; distinguished by its skylight windows, the Aerodyne sleeper cab was the first factory-produced sleeper cab with stand-up headroom (for both the W900 and K100). To commemorate the American Bicentennial, the VIT series was introduced in a limited-edition series of 50 (with each truck named after a state). 1980s-1990s In 1982 and 1984, respectively, the W900 and K100 underwent their most substantial revisions, becoming the W900B and K100E. While visually distinguished by the adoption of rectangular headlamps, the updates were centered around upgrading fuel economy, road handling, and reliability. In 1985, the Kenworth T600 was released by the company; in contrast to the W900, the T600 was designed with a set-back front axle and a sloped hoodline. While the latter initially proved controversial, the combination improved aerodynamics, fuel efficiency, and maneuverability. Intended as an expansion of the Kenworth model line, the success of the T600 would lead to the introductions of similar designs from multiple American truck manufacturers. In 1986, the T800 was introduced, adapting the sloped hoodline and set-back front axle for a heavy-duty chassis; the shorter-hood T400 was introduced in 1988 as a regional-haul tractor. In 1987, Kenworth introduced the Mid-Ranger COE, its first medium-duty truck. Shared with Peterbilt, the Brazilian-produced Mid-Ranger was derived from the MAN G90 (a wide-body version of the Volkswagen LT). In 1992,