500kHz WSPR over 5 days

The attached table shows the different stations that have reported my 500kHz WSPR in the last 5 days. In summary, 19 different stations in 8 different countries with best DX OH1LSQ (1736km) and last night LB9YE (1489km). My most recent calculation of my ERP is around 80-120mW. Who says 500kHz QRP into a very small antenna with a useless (?) indoor ground system doesn't work then? I can't wait for 472-479kHz to be released in the UK.