I think the best way to go about this may be to look up stats for names that you encountered a lot growing up. I knew a lot of girls named [name]Jessica[/name], [name]Ashley[/name] and [name]Jennifer[/name] growing up ([name]Katie[/name] too, but there are too many roots so I don’t want to use that one), and a lot of boys named [name]Matthew[/name], [name]Christopher[/name] and [name]Michael[/name].
If I use my birth year (1984) as the average, since certainly some I knew were born on either side. I looked up popularity percentages for that birth year and, funnily enough, the first three names I thought of for each gender were the three most popular names for that birth year.
1 [name]Michael[/name] 3.6108% [name]Jennifer[/name] 2.8051%
2 [name]Christopher[/name] 3.1995% [name]Jessica[/name] 2.5439%
3 [name]Matthew[/name] 2.6536% [name]Ashley[/name] 2.1507%
4 [name]Joshua[/name] 2.1463% [name]Amanda[/name] 1.8812%
Compare that with percentage stats for 2012:
1 [name]Jacob[/name] 0.9404% [name]Sophia[/name] 1.1531%
2 [name]Mason[/name] 0.9383% [name]Emma[/name] 1.0820%
3 [name]Ethan[/name] 0.8731% [name]Isabella[/name] 0.9852%
4 [name]Noah[/name] 0.8559% [name]Olivia[/name] 0.8923%
Today’s most popular names are significantly less used than those of 1984 (and that trend continues as you go back in time). With [name]Sophia[/name] in particular, you’re not getting the aggregate average of [name]Sophie[/name]/[name]Sofia[/name]/etc. but just for argument’s sake leaving them out: today’s [name]Sophia[/name] (spelled this way) at 1.15% is just a skosh more popular than 1984’s #10 [name]Elizabeth[/name] at 1.13% ([name]Heather[/name] was next at 1.19%).
So today’s [name]Sophia[/name] would expect to run in to as other Sophias as I ran into Elizabeths. I certainly knew/know a bunch, but not nearly as many as I knew Jessicas and Ashleys. This is largely a regional thing, as well, but I found the list pretty accurately represented the spread of names I ran into growing up.
#2 [name]Emma[/name] at 1.08% is between 1984’s #10 [name]Elizabeth[/name] at 1.13% and #11 [name]Megan[/name] at 0.94%
#1 [name]Jacob[/name] at 0.94% is actually in line with 1984’s #25, [name]Thomas[/name], at 0.94%
http://www.ssa.gov/cgi-bin/popularnames.cgi