For the 2021-2023 NHANES data, in order to remove TRT users, I screened out those with testosterone over 600 who also had LH below reference range. Apparently TRT lowers LH and FSH to near zero. I also removed some data that was probably in error.
So average testosterone in 2021-2023 was 451 ng/dl - no major difference from 2015-2016's average of 459 ng/dl.
2021-2023:
20-24: 536
25-29: 464
30-34: 476
35-39: 440
2015-2016:
20-24: 535
25-29: 556
30-34: 461
35-39: 466
2011-2012
20-24: 468
25-29: 438
30-34: 435
35-39: 392
2003-2004
20-24: 673
25-29: 537
30-34: 541
35-39: 589