Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_21158 ( "Player" text, "GP" real, "K. Ret." real, "KR Yds" real, "KR Avg." text, "KR TD" real, "KR LG" real, "P. Ret." real, "PR Yds" real, "PR Avg." text, "PR TD" real, "PR LG" real, "MFG Ret." real, "MFG Yds" real, "MFG Avg." text, "MFG LG" real, "MFG TD" real )

### Question ###
What is the pr avg, when kr lg is 49?

### Accurate SQL ###

SELECT "PR Avg." FROM table_21158 WHERE "KR LG" = '49'