Name: 920xt Power Grapher Data Field
Author: njrunnerfred

This is a data field that plots power in a color coded zone graph where:
zone 2 starts at 56% of FTP
zone 3 starts at 76% of FTP
zone 4 starts at 91% of FTP
zone 5 starts at 106% of FTP
zone 6 starts at 121% of FTP
zone 7 starts at 151% of FTP

FTP is configurable through the app settings. Instructions can be found here: https://apps.garmin.com/settingsHelp

FTP zones explanations can be found here: http://home.trainingpeaks.com/blog/article/power-training-levels
Special Thanks to Alex Belisle for keeping my spelling in check. 
Support Development: https://www.paypal.me/FreddyTan