What's the format of rates in api/v1/history

I’m using the api of cream finance for my data analysis project, and I couldn’t understand the format of all the rates in api/v1/history , the api is:

my questions are about :

    "cash": "4692244788045226373945", 
    "totalBorrows": "1280872039618210480467",
    "totalReserves": "3215400973174103874",
    "cashUSD": "15196003.1157475276738540725773137162358275",
    "totalBorrowsUSD": "4148150.0612462529913136616590214928996125",
    "totalReservesUSD": "10413.1914283795810830759321423736650775",
    "borrowRatePerBlock": "14978549763",
    "supplyRatePerBlock": "2515669643",
    "exchangeRate": "206820918217491973685538021",

what’s the unit of borrowRatePerBlock , supplyRatePerBlock and exchangeRate ? Do they need any processing? It looks like it’s not a “rate.”

Thank you.