2 Chr 36:11

בֶּן־עֶשְׂרִ֧ים וְאַחַ֛ת שָׁנָ֖ה צִדְקִיָּ֣הוּ בְמָלְכ֑וֹ וְאַחַ֤ת עֶשְׂרֵה֙ שָׁנָ֔ה מָלַ֖ךְ בִּירוּשָׁלִָֽם׃

Zedekiah was twenty-one years old when he became king, and he reigned in Jerusalem eleven years.