Why are demographics counted this way ? 65% Hispanic, 85% White ? I don't get it. Help !?

Okay here's the deal ill make it short. Im looking at the demographics of many different Florida cities but its so confusing. All statistics I look at have weird numbers like having 75% White population along with 45% Hispanics. Isn't it supposed to be out of 100% ? 75+45 = 120, how exactly are these demographics work. If I tell someone where I live there is 70% Blacks and 60% Hispanics it would not make much sense. If this is a dumb question please pardon me lol, this is my very first time looking at demographics.