Ninjatrader 7 Indicator (Tick data bid/ask %)

Build an indicator on the Ninjatrader 7 platform that display the % of Ticks within an interval (e.g.: 5min, 10000 volume, 1000 Ticks, etc) that were done at the Ask price, the Bid or the spread (i.e.: within the Ask and Bid). The only parameter is to select if it should display the % at the "Ask", "Bid" or "Spread" . The total of the values output by these three parameters must equal 100%. The indicator will be used to display on a chart (line oscillating between 0 and 100) and within Automated Strategies.