AGB Nielsen, who monitors the reach and quality of UHF signals, estimates that about 40% of the population in Java, the country's most densely populated island, is adequately covered by transmitters, as even are about 30% of Jakarta's inhabitants due in particular to the many high-rises which block out signals. The situation depicted by Nielsen's monitoring is uneven, but shows that even in major cities a large fraction of population is unable to receive (in good conditions) most local channels, and often not even all national channels (Exhibit 8). Thus one-third of inhabitants of Jakarta are limited to one-third of local channels theoretically available there, and 11% receive only five of the national channels or less – in this case mainly due to blockage by the city's many high-rises.