In the last period, Y12-Q3, the largest presented item is Symbian with Market Share of 2.3%. Based on the 2 presented items in the report, it seems that the entire Mobile OS market declined over the 7 quarters between Y10-Q4 and Y12-Q3. At that time span the element that declined the least was Windows Mobile OS with a slowdown of 78.24%, while the element that suffered from the biggest downturn is Symbian with 92.88% decline over the same period. This report represents data points consolidated from 3 sources: IDC, Gartner and StatCounter
IDC
Gartner
StatCounter