That is correct. Its called the Park Effect Index

Q. What does Park Effect Index mean?

A: An index of 100 means the park is average for that baseball stat that the Index corresponds to. An Index over 100 means that the park allows more than the average for that statistic. An index below 100 indicates that park allows less than the average amount of that statistic. The indexes used will represent the statistics gathered by Stats, Inc. during the last three year's games played at that park. In some cases the indexes represent just the last season or two if the park has recently changed it's configuration or if the park has not existed for three years.