You misinterpreted something here. The phone data is partial data as it is from a single mobile phone networks out of the four. It has been since updated to 2

You misinterpreted something here. The phone data is partial data as it is from a single mobile phone networks out of the four. It has been since updated to 2 out of the 4 (the other two supposedly respect their customer privacy). These number are not about Paris, which has a population of around 2 millions people, but for the whole metropolitan area. For the actual city of Paris 600 000 people left the city in a matter of days in relation to the lockdown announcement, or about 27% of population. https://www.insee.fr/fr/information/4477356 https://www.insee.fr/fr/information/4477356