This is pandasquad, so say you have 100 SP and you didn't use you account for one year and you came back to it you would have about 109 SP as your steem power receives interest (the interest rate changes constantly). So you have gained nearly $50 per year per 100 steem, so you account value would go up assuming a constant price. It's awkward to calculate as it compounds but also the rate constantly changes as well. If you have high SP its significant anyway, so it will be more important later on in your quest I guess. I had to use this account as my pandasquad one doesn't have enough steem power to comment or even top up SP due to bandwidth issues