NHW-20 (Type 20) i.e. 2nd Gen. My lowest is 4.4L/100km and that was last summer, the first summer. I just refuelled with the MFD showing 4.7L/100km. I travelled 708.5 km and refuelled 33.942 litres at 107.9 - 3.5 ¢/litre. So I'm hoping for 4.3 or lower this summer. I know of another who's getting 4.3L/100km in his old Prius (2003 model).
I consider myself fairly good, not an expert, but fairly good at maximising mileage. Checked with a "regular" folk and he was at 5.6L/100km during the summer