During his period of service, the school system was growing rapidly, adding five high schools.

Usually the students must complete a period of service in government institutions.

For those selected to serve, the period of service was three years.

Several significant modifications were made during the cars' period of service.

Its final period of active service was from 1961 to 1991.

Their period of service had an end; they remained, essentially, free.

Her first period of service to the agency was from 1996 to 2001.

Since 2006, the period of service has been six months.

His total period of service in the state Senate ran from 1981 to 1992.

After a period of political service, he became a Jesuit in 1580.