how do i get statistic data of a year ago?

Wowza Streaming Engine
1

hi, i use statistic REST API to view data a year ago.

url = http://127.0.0.1:8087/v2/servers/defaultServer/vhosts/defaultVHost/applications/live/monitoring/historic?start=2019-01-07

As you can see,

<string>average</string>
<list> 
<com.wowza.wms.stats.entry.StatsEntryApplication serialization="custom"> 
<com.wowza.wms.stats.entry.StatsEntry> 
<default> 
<data>
 <int>152</int>
 <int>120</int>
 <int>0</int>
 <int>0</int>
 <int>0</int>
 <int>0</int>
 <int>0</int>
 <int>0</int>
 <int>0</int>
 <int>0</int>
 </data> 
<dateTime>
 <iMillis>1553040000000</iMillis>
<iChronology reference="../../../../../../../../c/iChronology"/> 
</dateTime> 
</default>

first average data’s time is 1553040000000.

1553040000000 means 2019년 March 20일 Wednesday AM 12:00:00.

it’s not data of a year ago. how do i get statistic data of a year ago?