This info is in a lot of sources, but I just did this in R for fun with the main chromosomes.

library("BSgenome.Hsapiens.UCSC.hg38")
library("tidyverse")

hg38 <- BSgenome.Hsapiens.UCSC.hg38
seqnames <- setNames(seqinfo(hg38)@seqnames, seqinfo(hg38)@seqnames)

base_content <- map(seqnames, function(x) {
  freqs <- alphabetFrequency(hg38[[x]]) %>%
    as_tibble(rownames="letter") %>%
    filter(letter %in% c("A", "T", "G", "C", "N"))
  return(freqs)
})

base_content <- base_content %>%
  bind_rows(.id = "seqnames") %>%
  filter(str_detect(seqnames, "^chr[[:alnum:]]+$")) %>%
  group_by(letter) %>%
  summarize(value = sum(value)) %>%
  mutate(freq = value / sum(value))

And the results for one of the strands of human DNA for each main chromosome. The other strand for each chromosome would obviously just be the complement of these counts.

>base_content
# A tibble: 5 x 3
  letter     value   freq
  <chr>      <int>  <dbl>
1 A      867153993 0.281 
2 C      599043897 0.194 
3 G      601515125 0.195 
4 N      150630720 0.0488
5 T      869942666 0.282