According to Geoffrey Beene, the average life span of a dress shirt is 50 commercial launderings.
Here is an important tip to extend the life of a dress shirt. Machine wash dress shirts using a gentle cycle with luke-warm water. Do not dry-clean dress shirts. The chemicals in dry cleaning fluid will destroy the fabric or even turn dress shirts yellow. Instead, request that dress shirts be laundered.
I mention this as I suspect that most of my dress shirts have reached the limit of 50 commercial launderings. They are falling apart.