What is the size of downloaded JavaScript assets?

Analysis
1 
SELECT js_bucket, COUNT(*) pages FROM (    
  SELECT
    ROUND((bytesJS/1024)/50)*50 js_bucket
  FROM [httparchive:runs.latest_pages]
)
GROUP BY js_bucket    
ORDER BY js_bucket;

Above queries “buckets” pages in 50KB increments, which yields the following for Jul 2013:

I’ve clipped the tail in above graph - some sites are downloading 10MB of JS! But once you get over 2MB, it’s <10 sites per bucket.

SELECT  
  NTH(50, quantiles(bytesJS)) JS_med,
  NTH(75, quantiles(bytesJS)) JS_seventy_fifth,
  NTH(90, quantiles(bytesJS)) JS_ninetieth,
  NTH(95, quantiles(bytesJS)) JS_ninety_fifth,
FROM [httparchive:runs.latest_pages]

So, 171KB is the median, and 640KB for 95th percentile (also for Jul 2013 data).