How do you find the age of a Kimball Piano serial number 268366?

Generally, you will find about a 6 digit number stamped somewhere inside of the piano on the plate. This is the gold part of the piano called the harp. On some Kimball brands, they placed a name plate on the inside SIDE of the piano with the serial number located on that. A piano technician can look up the age but, we need the serial number to do so.