index - a numerical scale used to compare variables with one another or with some reference number. 1  margin of error, margin of safety, safety margin - the margin required in order to insure safety; in engineering the margin of safety is the strength of the material minus the anticipated stress.
Nutty Ways to Celebrate Squirrel Appreciation Day This Year. SQUIRRELS! Whether you love them or loathe them, National Squirrel Appreciation Day, January 21st, is a great time to take a few moments and learn about these nutty animals. If you count flying squirrels we have 10 tree species in North America.
Transit Driver Appreciation Day is Friday, March 18th, 2016. For hours on end, your driver manages to keep a schedule, check fares, give directions, announce stops, remember requests and more. All while safely maneuvering an extra-large vehicle through unpredictable traffic, tough weather conditions and some really tight spaces.