AD7172 sample rate question

I'm a bit confused about the AD7172 sample rate in the datasheet. It says "The output data rates range from 1.25 SPS to 31.25 kSPS" and also says "has a maximum channel scan rate of 6.21 kSPS (161 µs) for fully settled data". I don't quite understand which is the maximum sample rate, 31.25ksps or 6.21 kSPS. Currently, I'm going to use FPGA to read only one channel of the AD with 20 kSPS, so does this AD7172 can meet my sample rate requirement?