According to the information provided by treasurydirect.gov the rates for any treasury bill ranging from 4-52 weeks are all above 4%.

Looking at the 10 year/3month inversion spread , the graph is currently in the negative, meaning that the rates for short-term fixed income investment options are more favorable than long-term fixed income options. A negative inversion graph is reflected in the 4%+ rates for the most recent treasury bills.

Therefore, I'm assuming 4%+ rate is good for treasury bills.

I am wondering at what percentages most people draw the line between "poor", "average", and "good" investment rates.