Monster’s employment index of online job posting activity in the U.S. was unchanged in March with a reading of 143, the same as February, Monster Worldwide Inc. announced today. On a year-over-year basis, the index is up seven points from a reading of 136 in March 2011.

Sixteen of the 20 industries monitored showed growth, including transportation and warehousing, while public administration and educational services were among the lowest growth industries.

The index is based on a review of online job ads taken from a selection of websites, including Monster.com.