Sample rate division

Hi, I would like to know why "fm_deviation" is divided by SAMPLE RATE since that parameter depends only on the type of transmission. Thank you.

https://github.com/aricwang88/hackrf_WBFM_Transmit/blob/fde8e494a9634e6bd81ec777df604e005489416b/HackRF_WBFM_Transmit.c#L396C1-L403C3