Don't usually develop local photos., but travel ones still go into a nice book. I like the printing, choosing nice book, printing, writing little labels, planning the layout for the pics, sticking them on etc. The book itself ends up to be a nice product.
Would normally take a 1000 - 1500 photos for each week of travel, print about 10%, keep and disply about 5%.
<20% is also <40%, <10% is also <40%, <5% is also <40%, so if I choose <40% even when I print <1% still correct right? Then your statistics will be wrong. ;p
For me, depends on how much I shoot and what I shoot.. I will only print the images when I need to.. Like posez, travel photos will be printed... but after careful selection and some montage. Otherwise the album will be too thick (expensive). ;p