I spent some time over the Christmas holidays in 2009 studying participation levels in ARRL Sweepstakes CW and PH, comparing participation levels over the years. I was interested to learn that SS-PH first surpassed SS-CW in 1970, and that participation in each was about even during the 1970's. Participation in SS-PH has surpassed that in SS-CW since about 1980 through the present day. Participation in SS-CW peaked at 1677 logs in 1958. An Excel spreadsheet with the data I was able to harvest from the QST archives is available on the link sweepstakes.xls.