You seem to keep retrogressing past what we've already solved/shown solutions for. Why not build on the previously working solution in the previous thread remove-rows-text-at-the-bottom-of-a-csv-file? There I showed a simple way to return the values from the .csv file that mitigates the trailing disclaimer text essentially automagically. Instead you've returned to the previous case of holding all the file content in a cell array of cells which is exceedingly difficult to address owing to the need to get all the curlies and parens correct plus you can't do global addressing of cells with two-layer addressing to get subsets.
The previous file in the above thread used '-' as the date separator whereas this one uses '/' so that's one modification if choose to return the dates as y,m,d values rather than the string so that might mitigate using that altho you'll probably have to fixup the format string for datenum so it's likely a wash in writing generic code; you'll have to deal with the specific format at some point, anyway.
All that aside, start by first reading a single file and returning the specific information needed; namely the max for complete years, then look at wrapping that functionality over the files...
fmt='%*s %*d %4f/%2f/%2f %f %*[^\n]';
fprintf(fido,'%4d,%.1f\n', [yr mx].';)
You'll have to put in the housekeeping to create and open the output file(s*) then close after done and such, but the basic processing should be taken care of in the above...
You'll note I didn't bother to parse the station name from the file; that's just a complication of a bunch of meaningless text; I just parsed it from the input file name. The output file format is
(*) I basically presumed in the above the idea is to consolidate all these into a single file; hence the station and number of entries in each section to aid reading. If again want one per station, then as the sample in the other thread demonstated, find some common name-generating pattern here as well.
Also note the utility function isleapyr is one of my little helpers...