<P> Total: 11.1% Public sector: 35.7% Private sector: 6.6% Demographics Age 16--24: 5.1% 25--34: 10.0% 35--44: 13.0% 45--54: 14.4% 55--64: 14.9% 65 and over: 10.4% Women: 10.5% Men: </P> <Tr> <Th> Standard Occupational Classification </Th> <Td> <P> Management, professional: 11.9% Service: 9.2% Sales and office: 6.5% Natural resources, construction, and maintenance: 15.3% Production, transportation, and material moving: </P> 14.8% </Td> </Tr> <P> Management, professional: 11.9% Service: 9.2% Sales and office: 6.5% Natural resources, construction, and maintenance: 15.3% Production, transportation, and material moving: </P> <Tr> <Th_colspan="2"> International Labour Organization </Th> </Tr>

Which of the following is true of union membership in the united states since the 1980s