Good news for this Friday – lightning deaths have fallen dramatically since 1940. Using data from the NOAA NWS weather hazards page, reported lightning deaths in the US have declined to the point that they are now one-tenth of the number in the early 1940s.
I am not an expert on lightning deaths. However, I suspect one reason for the decline is due to changes in lifestyle including the end of WW II (less outdoor military training), more people working in offices, fewer people working on farms, etc. The other reason is the better communication over time on the general risk of lightning and better forecasts on the specific risk of thunderstorms.
Even with the decline in the number of deaths, it is still important to respect lightning and seek shelter when needed.
Data Source: http://www.nws.noaa.gov/om/hazstats/resources/weather_fatalities.pdf