There are two rough indicators of these factors. The traditional semaphore turn signals were replaced by conventional flashing directional indicators worldwide. The measurement occurs by using agreed key performance indicators (KPIs). Depuration of oysters can remove moderate levels of contamination of most bacterial indicators and pathogens. In recent years Rwanda has seen improvement on a number of key health indicators. Research emphasis was on chiefdoms and their associated archaeological indicators. Numbers are from The World Bank - World Development Indicators. A table of the indicators is below. South Sudan is acknowledged to have some of the worst health indicators in the world. It is among the surest indicators of further genocidal massacres. Latvia performed the best according to all indicators.