an increasing trendp < 0.01
a decreasing trendp < 0.10
Spatiotemporal Characteristics of Earthquake Disaster Frequency As seen in Figure 2 compared with a slightly decreasing trend in the number of seismic events that occurred in the mainland of China ( Figure 2 a), there is an increasing trend ( p < 0.01, M-K trend test), but with fluctuations, in the annual total number of earthquake disasters in China during 1950–2017 ( Figure 2 b); for example, there is a decreasing trend ( p < 0.10) during 1986–2017 ( Figure 2 b).