line graph in the terminal with gnuplot

I wrote a command that outputs data in tabular format, looking like this:

$ rb services metrics app-prod | head
time                 memory       cpu    
2024-01-29T07:19:00Z 191668346880 39688  
2024-01-29T07:20:00Z 191886577664 39953  
2024-01-29T07:21:00Z 191411822592 38933  
2024-01-29T07:22:00Z 190887628800 38824  
2024-01-29T07:23:00Z 192347156480 39501  

I wanted to print the CPU column to the terminal with a nice line graph. Here's where I ended up:

rb services metrics app-prod |
  gnuplot -e '
    set terminal pngcairo size 2048,768; 
    set datafile separator " ";
    set xdata time; set timefmt "%Y-%m-%dT%H:%M:%S"; 
    set format x "%Y-%m-%d\n%H:%M:%S";
    plot "<cat" using 1:($3/1000) notitle with lines' |
  icat --align left

and here's what it looks like: