Last month, Amir Johnson, David Lee, Perry Jones, Jae Crowder and Jonas Jerebko were introduced to the media in Boston smiling to the cameras with their new Celtic jerseys.

For Jones and Johnson, not only the colors were new but also the numbers. Johnson will wear No. 90 instead of the 15 he used at Westchester HS and Toronto. Jones, who played with No. 3 throughout his high school and pro career, will don No. 38.

Crowder and Jerebko, who are not new to the Celtics, will return with jersey numbers they had never worn for any other team before.

That’s not an exception to the rule but actually a pattern with the Celtics. The storied franchise has retired the jersey number of 21 different players. Factor in teammates that were already there before they arrived and newcomers in Boston have very little chance of wearing their favorite number.

How little?

We did research on the 105 NBA players that have competed for Boston between 2005-06 and 2014-15 and found out only 24 (22.8 percent) were able to play with their usual number in a Celtic jersey.

This is the full list.